A toolkit for acid upland soil fertilitymanagement in Southeast Asia

Soil Fertility Kit

Thomas Dierolf, Thomas Fairhurst and Ernst Mutert

Introduction

Process and practical tools

Principles and methods

Essential information

Soil Fertility Kit: A toolkit for acid upland soil fertility management in Southeast AsiaHandbook SeriesT. DierolfT. H. FairhurstE. W. Mutert

Copyright © 2000

by Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH; Food and AgricultureOrganisation; PT Katom; and Potash & Phosphate Institute (PPI), Potash & Phosphate Instituteof Canada (PPIC).

All rights reserved

No part of this handbook may be reproduced for use in any other form, by any means, includingbut not limited to photocopying, electronic information storage or retrieval systems known or tobe invented. For information on obtaining permission to produce reprints and excerpts, contactthe Potash & Phosphate Institute.

Limits of liability

Although the authors have used their best efforts to ensure that the contents of this book iscorrect at the time of printing, it is impossible to cover all situations. The information is distributedon an ‘as is’ basis, without warranty. Neither the author nor the publisher shall be liable for anyliability, loss of profit, or other damages caused or alleged to have been caused directly orindirectly by the following guidelines in this book.

Type setting by Tham Sin Chee.

First edition 2000

ISBN xxx-xx-xxxx-x

About the publisher

Our mission is to develop and promote scientific information that is agronomically sound,economically advantageous and environmentally responsible in advancing the worldwide useof phosphorus and potassium in crop production systems.

PPI books are available at special discounts for bulk purchases. Special editions, foreignlanguage translations and excerpts, can also arranged – contact PPI’s East and SoutheastAsia Programs office (refer to back cover) for more information.

Printed by xxxxx

Acknowledgements

(i)

Contents

(ii)

Foreword

(iii)

1

In this section

A-1 The Upland Environment in Indonesia

A-2 The Link Between Poor Soil Fertility Management and thePoverty Spiral

A-3 Improving Soil Fertility to Get Out of the Poverty Spiral

A-4 Characteristics and Distribution of Acid, Upland Soils ofIndonesia

A-5 How to Use This Handbook

IntroductionThe acid, upland soil farmingenvironment in Indonesia’souter islands

2

Plate A A sequence of six steps that lead to the degradation of acid, upland soil.

2 Timber is extracted using heavy equipment thatdamages the fragile soil.

6 The land is abadoned and colonized by alang-alang(Imperata cylindrica).

5 The farmer may crop the land twice before soilfertility is exhausted.

4 The remaining trees and vegetation are burnt tofertilize the farmers crops.

3 After logging, the land is prepared for transmigrantfarmers.

1 Forest land is opened up for timber extraction bytimber companies.

1

5

3 4

2

6

3

A-1 The Upland Environment inIndonesia

About 30% (or ~58 M ha)of the land inIndonesia is used for agriculture (Table A-1).13% of this land is classified as lowland andis mainly used for stable and productiveirrigated rice systems. Lowland rice soils(paddy soils) are more fertile compared toupland soils . These lowland areas are

supported by a well-developed infrastructureof roads, markets, electricity, water supply,agricultural supply shops, and health clinicsand schools (Plate A-1a, b). The area underirrigated rice cultivation cannot be increasedeasily and the situation is further aggravatedas large areas of the most productive rice landsare converted to industrial use and housingeach year.

The greatest potential for future increases inagriculture production and productivity inIndonesia lies in the remaining 87% (or ~50 Mha) of agricultural land classified as uplandor rainfed land. Upland soils occupy 26% ofthe total land area in Indonesia and are foundmainly in Sumatra, Irian Jaya and Kalimantan(Table A-1). At present, only 18 M ha of theuplands are being used, while >30 M ha are

either under fallow or man-made savannah(alang-alang sleeping land ) (Table A-1). Inaddition to its low fertility status, the uplandsare also characterized by diverse, potentiallyunstable agricultural systems (Plate A-1c).These areas often have a poor infrastructure,severely limiting the farmers access toagricultural supplies, services and information(Plate 1c, d).

The fragile upland soils are vulnerable todegradation when cleared of their protectiveforest cover (Figure A-1).

A-2 Characteristics andDistribution of Acid, Upland Soilsof Indonesia

Distribution

About 22% (or ~42 M ha) of the land area inIndonesia is made up of low pH soils with lowfertility status and the potential for aluminiumtoxicity (Figure A-2).

Characteristics of main soil typesThe main soil types are red-yellow podzolicsoils and, to a lesser extent, Latosols andAndisols (Table A-2, Plate A-3).

Table A-1 Distribution of land types in the islands of Indonesia. The greatest potential forfuture increases in agriculture production and productivity lies in 87% of the agricultural landclassified as upland or rainfed land.

dnalsIdnalwoL dnalpU rehtO latoT aeradnaL

ah000, %avaJ 165,3 788,5 177,3 912,31 7

artamuS 329,1 364,41 779,03 363,74 52

natnamilaK 379 299,7 530,54 000,45 82

isewaluS 277 128,5 205,21 590,91 01

aupaP 9 444,01 747,13 002,24 22

sdnalsirehtO 673 304,5 092,9 960,51 8

latoT 416,7 010,05 223,331 649,091 001

aeradnal% 4 62 07 001

dnallarutlucirga% 31 78 001

4

Plate A-1

a) Lowland irrigated ricesystems produce 94% ofIndonesia s rice. Thelowlands have goodinfrastructural support.

b) Agriculture input supplyshops like this one in alowland rice production areaare often not found in farmingdistricts in the uplands. Withonly limited access to inputs,farmers are often unable toadopt new technology.

c) The uplands arecharacterized by diverse,potentially unstableagricultural systems.

d) As part of the package , atransmigrant farmer isprovided with a temporaryhouse. He will need totransform the productivity ofhis land rapidly in order togenerate sufficient funds tobuild a permanent house.

a

b c

d

Figure A-1

Representation of the threemain landuse systems inIndonesia.

Under forest-tree crops and lowlandirrigated sawah, the soil ispermanently covered and protected.The intermittently covered uplandsare exposed to soil degradation fromerosion, surface runoff andexcessive temperatures.

5

� Red-yellow podzolic soils (USDA Ultisols)

Red-yellow podzolic soils are clayey-textured with a red or yellow subsoil andare usually found in landscapes with rollinghills. Intensive weathering and leaching dueto high temperatures and rainfall overthousands of years have removed nutrientsfrom the soil. As a result, the red-yellowpodzolic soils are usually poor in N, P andK. Al-toxicity and P fixation are alsocommon in these soils (Part 2-1).

� Latosols (USDA Oxisols, Inceptisols)

Latosols are usually found in the flatterareas. They are older and more depletedof nutrients than red-yellow podzolic soils.However, their physical properties and soilstructure often make them more suitablefor agricultural use. These soils sometimesshow strong P sorption.

� Andosols (USDA Andisols)

Andosols develop from volcanic ash nearvolcanoes. They are much younger than

Table A-2 The main soil types in indonesia, (particularly in Sumatra, Kalimantan andPapua) are acid, low fertility, red-yellow podzolic soils and latosols.

dnalsIcilozdopY-R slosotaL slosidnA srehtO aerA

% ahM

avaJ 5.2 4.12 4.6 7.96 2.31

artamuS 7.33 3.41 8.5 2.64 4.74

natnamilaK 9.62 3.8 3.2 5.26 0.45

isewaluS 8.7 0.51 8.0 4.67 1.91

ayaJnairI 4.82 9.0 0.0 7.07 2.24

srehtO 4.12 2.7 7.0 7.07 1.51

latoT 9.42 6.9 7.2 8.26 0.191

Figure A Map of Indonesia showing extent of acid soils.

6

red-yellow podzolic soils and latosols. Theyare usually more fertile than podzolic soilsand latosols, but they also be very infertile.Andosols have the capacity to fixphosphorus, and it may be necessary toapply large amounts of P fertilizer to correctP deficiency (Part 2-7).

A-3 The Link Between Poor SoilFertility Management and thePoverty Spiral

In the past, the traditional slash-and-burnagricultural system practiced extensively onacid, upland soils was sustainable. This wasbecause at any one time, farmers made useof only a small part of the total land area to

Plate A-4

Typical acid upland soilprofiles in Indonesia.

support a subsistence (i.e., not cash crop)economy (Plate A-5 ).

With the move toward a cash economy, andthe pressure on land availability in the uplandsdue to the population increase, these systemsare no longer unsustainable. The fallow periodis seldom long enough for complete restorationof soil fertility, and nutrients removed in cropproducts, surface runoff, and erosion, are notbeing replenished by mineral fertilizer inputs.These are the main reasons for declining soilfertility in slash-and-burn agriculture as it ispracticed today (Figure A-3).

Slash-and-burn and much of the fallow-basedagriculture have developed into unsustainable,low productivity agricultural systems in theuplands (Plate A-6a). Often, crops can only

Plate A-5

Slash-and-burn agriculturalsystems are sustainable onlywhere sufficient land isavailable for the requiredfallow period.

7

Figure A-3

The downward spiral to thepoverty trap for upland farmfamilies is closely related tolow soil fertility.

Plate 1-6

a) Short fallow periodsresult in a decrease in soilfertility, low productivityfarming systems and humanpoverty.

b) The only rice plant ableto grow and thrive in this fieldis planted into soil enrichedwith nutrients contained inash.

c) Inappropriate agriculturaltechniques in the uplandshave led to environmentaldestruction, land degradationand human poverty.

a b

c

8

grow in patches of soil enriched by the ashesfrom fires used to burn the fallow biomass(Plate A-6b). Inappropriate agriculturaltechniques have also led to environmentaldestruction, degradation, and poverty (PlateA-6c). A downward spiral eventually leadsupland farm families into a poverty trap cycleof low inputs, low yields, and low income(Figure A-3).

A-4 Improving Soil Fertility to GetOut of the Poverty Spiral

It is possible to develop sustainable, productivefarming systems in the uplands. The mostsuitable farming systems are based either ontree crops or mixed crop-livestock systems

(Plate A-7) which, when properly implemented,can be as profitable to the farmer as lowlandrice cultivation.

A key to achieving and maintaining intensified,integrated, and productive systems is theproper management of soil fertility. Figure A-1showed how nutrient depletion results in yieldand income reduction. This situation can becorrected by first increasing soil fertility to allowproductive cropping, and then maintaining soilfertility, by replacing nutrients removed and lostfrom the upland agricultural system usingproper crop residue management techniques,and through the addition of mineral fertilizers.

Plate A-7

a) With proper soil, crop,water, and fertilizermanagement, the uplandscan sustain productiveagricultural systems such asthis tree-crop system.

b,c,d,e) Productivity may beincreased substantially whenproperly managed livestockare integrated into uplandfarming systems.

a

b

d

c

e

9

Part 1 A Cyclic Process and Practical Tools to Improve SoilFertility Management in Acid UplandsStep 1 Confirm that the soil is an acid, upland soil

Step 2 Identify major soil fertility problems

Step 3 Make recommendations for improvements

Step 4 Test, evaluate and follow-up the recommendations

Part 2 Principles and MethodsChemical Characteristics of Acid, Upland Soils

Physical Characteristics of Acid, Upland Soils

Biological Characteristics of Acid, Upland Soils

Causes of Upland Soil Fertility Problems

Plant Nutrition and Nutrient Cycles

Nutrient Requirements of Integrated Upland SystemsSoil Fertility Management

Nutrient Sources

Biological Soil Fertility Management

Indirect Management Effects on Soil Fertility

Part 3 Essential Information for Upland Extension WorkersSoil and Plant Sampling Analysis

Soil Chemical Properties for 45 Crops

Critical Leaf Nutrient Concentrations for 45 Crops

Nutrient Uptake and Removal for 45 Crops

Properties of Nutrient Sources (Residues and Fertilizers)

General Fertilizer Recommendations and Examples of Field TestsManagement of Micronutrients

Balance Nutrient Recommendations for 45 Crops

Timing of Fertilizer Applications

Fertilizer Storage

List of Important Legume Species for Acid, Upland Soils

English, Indonesian and Latin names for Important Crop Species

List of Conversion Factors

Glossary of Terms

A-5 Who should use thishandbook

This handbook will equip extension workerswith methods, principles, and tools so that they

can assist farmers manage the quantity andavailability of nutrients in acid, upland soilswhere accurate and complete recommenda-tions based on soil and plant testing are notpossible.

10

11

In this section

1-1 Outline of the Process

Step 1: Confirm that the Soil is an Acid, Upland Soil

Step 2: Identify Major Soil Fertility Problems

Step 3: Make Recommendations for Improvements

Step 4: Test, evaluate and follow-up the recommendations

Part 1

A cyclic process and practical toolsto improve soil fertility managementin acid, upland soils

12

2 P (left) and K (right) deficiencies are endemic whenthese soils are cropped.

3 Deficiency symptoms in maize are useful fordiagnosing soil fertility problems.

1 There are more than 11 M ha acid, upland soils inIndonesia.

Plate 1 One recommended sequence for acid, upland soil rehabilitation.

1 2

3 -P -K

5 Apply and incorporate ~1 t rock phosphate ha-1.

5

6 Rehabilitate the soil before cropping by usinglegume cover plants.

6

4 Install soil conservation measures to reduce theloss of added nutrients.

4

13

7 Legume cover plants respond well to the rockphosphate application.

8 Biological activity in the soil increases due to thelegume cover plant litter fall.

12 The residual effect of rock phosphate persists overseveral crop seasons.

11 Unproductive acid, upland soils can betransformed into productive land.

9 Soil particle aggregation is improved due toincreased biological activity.

10 The response to N and K fertilizers is large afterapplying rock phosphate.

Plate 1 ...continued.

87

9 10

1211

14

� Bappeda Tk. I and II (Land Unit and SoilMap at a scale of 1:250.000)

� LREP I and Land Systems and LandSuitability maps (scale 1:250.000)

� Balai Pengajian Teknologi Pertanian(Institute for the Assessment ofAgricultural Technology) agro-ecologicalzone maps.

� Local Universities (soil science faculty).

Information is usually available in differentforms and scales and must be carefullyinterpreted. If soil maps and/or soil analysisdata are available for the area, use thefollowing criteria to determine whether acid,upland soils are present:

1 Soil classification. A list of acid soil typesis shown in Part 3-1.

2 Soil chemical data: Check available soilanalysis data. If the pH is between 4.0—5.5, and the soil test is <15 (Bray II), <7(Olsen 3), < 2 (ammonium acetate/aceticacid) mg P kg-1 soil, it is likely to be anacid upland soil.

Location: acid, upland soils are:

� most likely to occur in areas formerlyoccupied by forest, between 50—150 mabove sea level, on rolling or undulatingtopography, and

� least likely to occur near coastlines onsandy soils, in lowland swamps orfrequently flooded soils, or whereirrigated rice is grown.

Regional-level soil information should only beused to give you an idea of what types of soilsare found in your area. If all the soils in yourarea are peat or swamp soils, this handbookis not suitable for you. If you conclude thatacid, upland soils occur in your subdistrict ordistrict, move on to the next step.

Step 1.2 Get farm-level soil information

The next step is to check whether the soil ona particular farm is an acid, upland soil type.The soil type will be influenced by its positionin the landscape (e.g., less acid soils in thevalley bottom, more acid soils on hill slopes),

1-1 Outline of the process

A participatory process for improving soilfertility management requires that the farmfamily and extension worker do the following:

1 Discuss the general soil fertility of a farmand the options available to thehousehold for improving soil fertility, and

2 Select techniques from a range ofoptions and test them in farmers fields.

On the first attempt, go through all the stepslisted below. The procedure can be completedmore quickly when you have become morefamiliar with the process.

Go through the procedure step-by-step.Important information is gathered in Steps1.1—2.6 shown below.

Compile the results of your information in Table1-9. Then examine the evidence and make adiagnosis.

The first part of the process is like a detectivetrying to solve a case. Examine all theevidence, question the appropriate witnessesand suspects, and ask the right questions!

Step 1 Confirm that the soil is anacid, upland soil

Step 1.1 Get regional-level soilinformationFirst, find out about the basic soil types in theregion (province, district, or subdistrict level).This is to determine the likelihood that thefarms that you will visit may be on acid, uplandsoils. This information should be madeavailable to extension workers by the district-level center for extension and information.

In Indonesia this information can be obtainedfrom:

� Centre for Soil and AgroclimateResearch, Bogor. The Centre has soilmaps of all of Sumatra, Java, and manyother parts of Indonesia.

� Kanwil BPN Tk. I (Land Use Maps atscales of 1:25.000 and 1:100.000)

15

Table 1-1 Activities involved in the process. The section numbers indicate where thesetopics are discussed in further detail in Part 2.

petS ytivitcA esopruP

1 .liosdnalpu,dicanasiliosehttahtmrifnoC

1.1nonoitamrofnilanoigerteG

.slios-busehtniruccosliosdnalpu,dicafienimreteD

.tcirtsidrotcirtsid

2.1lioslevel-mrafteG

.noitamrofni,dicanaebotylekilsiliosdleifehtfienimreteD

.liosdnalpu

2lioswohyfitnedidnasmelborpytilitrefliosrojamesongaiD

.devorpmiebnactnemeganamytilitref

1.2dnasksat:sisylanaredneG

.lortnocetairporppaehttahtostahwseodohwenimreteD

.devlovnierasrebmemylimaf

2.2tneirtundnadleifehtfopaM

.dlohesuohehtniswolfgnimrafehtfognidnatsrednullarevonapoleveD

.tiniswolftneirtundnametsys

3.2ytilitrefliosdlohesuoH

.tnemeganam.secitcarpdnaegdelwonkremraftuobanraeloT

4.2 .yrotsihytilitref/gnipporCtsapfostceffeelbissopehtenimreteD

.ytilitrefliosnotnemeganam

5.2ycneicifedtneirtuN

.smotpmysotdeentahtsmelborpytilitreflioslacitircyfitnedI

.detcerroceb

6.2ytilitrefliosetaulavE

.secitcarpebdluoctahtsecitcarptnerructuobanraeL

.devorpmi

7.2 .sisongaiDdnasmelborpytilitrefelbissopenimreteD

.devorpmiebdluoctahttnemeganam

3 .secitcarptneserpnoevorpmiotsnoitadnemmocerekaM

1.3ekamdnassucsiD.snoitadnemmocer

smelborptneirtunemocrevootsyawdnemmoceR.secitcarptnerrucevorpmiotdna

4 .snoitadnemmocerehtnopu-wollofdnaetaulave,tseT

1.4noitadnemmocerehttseT

.mrafehtnootdlohesuohehthtiwsnoitadnemmoceresoohC

.snoitidnocmrafrednutset

2.4ehtetaulavednarotinoM

.remrafehthtiwtsetdlohsuohehthtiwstlusertsetehtetaulavE

3.4 .gnilpmasdleiYtnereffidehtnidleiyerapmocdnaerusaeM

.stnemtaert

4.4 .tegdublaitraP

tnereffidehtfostifenebdnatsocehtetaluclaC.tnemtaert

stluserehttpada/tpodaotdlohesuohehttsissA.sdlohesuohrehtohtiwerahsdna

5.4htiwtsetdleifehtpu-wolloF

.remrafehtsecitcarpdednemmocerehtrehtehwetaulavE

.elbatiuserew

6.4tsetdleifehtgnitanimessiD

.stluserrehtohtiwnoitcapu-wollofrofnalpassucsiD

.egallivehtnisremraf

16

and the material from which it is derived (e.g.,limestone, volcanic ash, granite rocks, etc.).Because of the range of parent materials inmountainous areas, there may be a range ofdifferent soil types present, even in one village.

Four other characteristics provide furtherevidence that the soil on the farmers field isan acid, upland soil:

1 the soil has a pH ≤5.5,

2 the soil has reasonably good drainage(i.e., it is not frequently flooded),

3 the soil is a mineral soil (i.e., it does nothave a thick organic layer at its surface),and

4 the soil is probably not of recent volcanicorigin (i.e., the soil is not located near anactive volcano).

Measure the soil pH and examine weedand crop vegetationMeasure the soil pH with a low cost field pHtest kit (e.g., Hellige Pehameter, Plate 1-1a).Refer to Part 3 for proper sampling techniques.

If you cannot measure soil pH, make thefollowing observations and enquiries:

1 Examine the native vegetation andidentify indicator plants and weeds andevaluate the growth of crop and weedplants. Some plants such as the Straitsrhododendron (MelastomaMalabathricum), alang-alang (Imperatacylindrica) and tropical bracken(Dicranopteris linearis) are indicators ofacid soil conditions (Plates 1-1).

2 If crops tolerant of acidity and high Alsaturation (e.g., rubber, cassava) aregrown on a large scale in the area, thenthe soil is probably acid (Table 3-5).

3 Ask the farmer if he has applied limewithin the past five years and if so, howmuch? An application of 1 t ha-1

agricultural lime (20—30% CaO) willincrease the pH of the top soil (0—20 cm)by 0.25—0.5 pH units. If the land iscontinuously cropped, pH will decreaseby 0.5—1 pH units over the following fiveyears.

4 The presence of limestone rock on oradjacent to the field indicates that the soilprobably has high pH and is not an acidsoil. However, acid soils also sometimesoccur in the vicinity of limestone outcropsin so-called karst landscape.

Check the soil drainageAcid, upland soils are usually not flooded forlong periods of time. If the soil is always floodedor frequently underwater for long periods at atime, it is probably not an acid, upland soil.Presence of sago palm (Metroxylon sagu) orgelam (kajuput oil tree, Melaleucaleucadendra) indicates periodically floodedsoils.

Move on to the next section if you concludethat the soil is probably an acid, upland soil.

Step 2 Identify major soil fertilityproblems

Step 2.1 Household and gender analysis:tasks and control

Identify which household member does thevarious farm tasks, makes decisions, and hasaccess to resources that are related to soil andcrop management (Plate1-2). This will guideyou to talk with the appropriate householdmembers when asking questions about soiland crop management practices and whenselecting recommendations to test.

� Example 1. If you want to estimate howmuch forage is removed from a fieldduring the year, make sure you ask theperson that cuts the forage! In manycases, a child or the wife (not thehusband) may cut and carry forage fromthe field to the cow shed.

� Example 2. Discuss proposals tomodify fertilizer rates with the person whodecides on how much fertilizer topurchase before testing therecommendation in the field!

The checklist in Table 1-2 provides useful hintsto help you identify the appropriate person tocontact. Change or add to the checklist to suit

17

your needs. Use the checklist in a groupinterview to acquire a general picture of thevillage or with a single family to develop adetailed picture of the household. In all cases,you should involve both male and femaleparticipants, adults, and young people involvedin the tasks listed in the checklist. It may behelpful to divide a large group by gender and/or by age to get a more realistic picture andfoster open discussion.

Step 2.2 Map nutrient flows on the farm

Together with the farm household, draw a mapand discuss the major nutrient flows in thehousehold. Fertilizer, crop biomass, andanimal manures are usually the major sourcesand forms of nutrients in a farm household(Figure 1-1) (Part 2-4).

Follow the following approach described inFigure 1.1:

� Draw each of the farmers fields,including the home garden, and indicatetheir relative size and distance from eachother.

� Mark the major infrastructure (e.g., home,animal stall, field shed, etc.) on the map.

� Indicate the major crops (e.g., food, cash,forage, etc.) grown on each field.

� Indicate the number of animals of eachtype of livestock in the location wherethey spend most of their time.

� Indicate the amount of fertilizer appliedfor each field every year.

� Indicate how much and what type ofvegetation (e.g., grain, fruit, biomass) isremoved from each field every year.Draw a line to link the source of thematerial and its destination. Material isusually either taken to another field/stallon the farm or sold to another farmer.

� Indicate approximately how much animalwaste is deposited in each field or animalstall. If manure produced on-farm ismoved from the animal shed to a field,indicate this with arrows.

� Indicate any other large addition orremoval of nutrients in other forms on themap.

Plate 1-1

a) A handheld field pH meteris a simple and accurate wayto identify an acid soil.

b) Straits rhododendron(Melastoma malabathricum)is an indicator of acid soilconditions.

c) P-deficient alang-alang(Imperata cylindrica) leaveslying on an eroded, acid soil.

d) Dicranopteris linearis andalang-alang indicateimpoverished soil

a b

c d

a b

c d

18

seodohW?ksateht

sekamohWnoisicedehtwohronehw

ehtodot?ksat

ytivitcA H W C O H W C O

rezilitreF

srezilitrefsesahcruP

setarnoitacilppA

gnitnalptarezilitrefseilppA

gnipporcgnirudrezilitrefseilppA

kcotseviL

kcotsevilsezarG

dleifmorfreddofseirrac/stuC

kcotsevilsdeefllatS

llatsniserunamlaminaseldnaH

dleifehtoterunamseirraC

porcehtoterunamseilppA

sporC

nworgerasporctahwsediceD

.)gnieoh,gnihguolp(gnitnalprofliosseraperP

.)dleifehtotdenruter,delip.g.e(seudiserporcseganaM

wartsecirseganaM .)elttacotdef,denrub.g.e(

)evitaler,ruobalderih,.g.e(rehto=0;nerdlihc=C;efiw=W;dnabsuh=H

Table 1-2 Use this checklist to make sure that you talk to the appropriate person whenasking questions about farm management and when deciding on recommendations to test.

After drawing the map, try to answer thefollowing questions:

1 Are more nutrients being removed oradded to each field? Are more nutrientsbeing removed or added to the farmingsystem?

2 Is animal manure being applied to any ofthe fields? If yes, why? If no, why not?

Step 2.3 Ask about the household s soilfertility management

You will need to both observe and askquestions of household members in order tounderstand the soil fertility management of afarm. Some farmers may already know muchabout the soil on their farms and what soilfertility management techniques have workedwell in the past. (Remember that the bestfarmers in the village likely produce crop yieldstwo times as large as the average farmer!) This

19

can be valuable information to help diagnosesoil fertility problems and ways to improve soilfertility management. Ask open questions touncover aspects of their soil fertilitymanagement that might be overlooked if youask closed questions (Table 1-3a). You mayadd or remove questions from Table 1-3b asnecessary.

This information can be useful in two ways:

1 It provides you with local knowledge andpractices that may not be included in thishandbook.

2 Much of this information will be useful foranswering questions that appear in thediagnosis process in Step 2.7.

Use some of this information to improve themap prepared in Step 2.2.

Step 2.4 Ask about the cropping/fertilizerhistory

Acid upland soil properties, especially thoseaffecting soil fertility (Parts 2-1 to 2-3) can bechanged greatly by farm management. Thissection will show you how to collect informationon the farmers past field management, whichyou will then use to estimate whether or notthe present soil fertility management issustainable.

Answers to the following questions arerequired:

1 Are the soils low in native soil fertilitystatus?

2 Is there a large net loss/removal ofnutrients from the field?

3 Have any large amounts of lime, Pfertilizer or crop residues been applied tothe soil in the past five years.

Cropping HistoryDraw up a cropping history to find out whethersoil fertility is limiting crop yields. Table 1-4ashows an example how this data can becollected. The farmer s last four crops(beginning with the most recent) were maize,maize, soybean, and maize. Yields for eachcrop were recorded. Next, ask if there wereany major pest, disease, drought, or poor stand(from poor seed quality) problems for any ofthe crops. This helps to eliminate causes oflow yields other than low soil fertility. Finally,ask what are average, good yields for the cropin the area. Table 1-4a shows that maize yieldshave been declining but they are still abovethe average, good yields for maize in the area.Using Table 1-4b to interpret this information,we see that this situation falls under box #3,

Figure 1-1

Together with the farmhousehold, draw a map toprovide a basis fordiscussion on the majornutrient flows into theirhouseholds.

20

meaning that there are no major soil fertilityproblems, but that there is probably poor soilfertility management.

In fact, you may ask the farmer to draw theyields on a graph (Figure 1-2). To do this, firstask what the average, good yields are for thearea and draw a horizontal line across themiddle of a blank graph. Label the vertical axisas crop yield, and have the yields range from0 t ha-1 to about double the average, goodyields for the area (e.g., if average, good yieldsfor the area is 4 t ha-1, then label the verticalaxis from 0 to 8 t ha-1; the horizontal linerepresenting average, good yields will be at 4t ha-1). Then ask the farmer to draw a dot thatrepresents the crop yield somewhere aboveor below the horizontal line for each time thecrop was grown (do not include crops that hadmajor problems with pests, drought, disease,or poor stands). The dot should be placeddepending on what the crop yield was ascompared to average, good yields for the area.Connect the dots for each crop and you willhave a trend line that may look similar to oneof the lines shown in Figure 1-2. Each croptype should be done on a separate graph.

Nutrient BudgetCalculate a simple nutrient budget todetermine whether the current managementsystem results in the net addition or removalof nutrients from the field. Systems are notsustainable when more nutrients are removed

in the harvested product than are added inmanures and fertilizer (Part 2-4).

Table 1-5 shows an example of a nutrientbudget for a farmer who planted a crop ofmaize followed by groundnut in a 1-ha fieldfor one year. The farmer applied 125 kg ureaand 50 kg TSP to the maize; 25 kg urea and25 kg TSP to the groundnut; and 2 t fresh cattlemanure to the maize. Use the tables in Part 3to convert mineral and organic fertilizer tonutrients (e.g., urea to N) as well as to calculatethe amount of nutrients removed in either grainor biomass.

In this system, the farmer removed all of themaize grain, stalks, and leaves, but onlyremoved groundnut grain. Although groundnutstems and leaves were returned to the field,they are not counted as nutrient additionsbecause the nutrients contained in thegroundnut stems and leaves originated fromthe field itself (Part2-4)!

In this field, there is an overall loss of N and K.Nutrient management in this field isunsustainable, and because the low yieldsindicate that field is already poor in nutrients,yields will probably decline in subsequentseasons.

Finally, do not forget to ask if any additions ofP fertilizer, lime, or organic materials obtainedfrom off-farm sources were applied during thepast five years. If large amounts of any of these

Plate 1-2

Knowledge of the roles andresponsibilities in thehousehold is required toidentify the appropriatepeople when obtaininginformation or makingrecommendations.

21

materials were added within the past fiveyears, they could help to explain present highyields despite poor management.

Step 2.5 Identify nutrient deficiencysymptoms

Nutrient deficiency symptoms can be used asa diagnostic tool to demonstrate soil fertilityproblems to farmers (Plate 1-3). Crop plantslacking a particular nutrient often exhibitdeficiency symptoms specific to a particularnutrient (Part 2-5 and Part 3-4).

Important concepts

If leaf deficiency symptoms are detected, plantgrowth has probably already been affected bya shortage of nutrients. Similarly, a plant mayalready need more nutrients before deficiencysymptoms become evident (referred to ashidden hunger). It is often difficult to distinguishnutrient deficiency symptoms from diseasesymptoms and other plant disorders.Furthermore, diseases are often more

prevalent where crops are poorly supplied withnutrients!

Apart from N, P, and K, other nutrients (e.g.,Mg, S, and sometimes Ca) may also bedeficient and present leaf deficiency symptomsin crop plants. Table 1-6 summarizes theconditions under which the various nutrientslimit crop growth.

Maize is an excellent indicator of deficiencysymptoms. A set of illustrations for identifyingnutrient deficiencies in crop plants is providedin Part 3-4. When identifying nutrient deficiencysymptoms, it is important to distinguishbetween older and younger leaves. Using yourknowledge about the general fertility of acid,upland soils, past soil and crop managementpractices, and the incidence of leaf nutrientdeficiency symptoms, you should be able todetermine whether N, P, K or other nutrientsare deficient.

1 2 3 40

1

2

3

4

5

6

7

8

9

10

Cro

p yi

eld

(t h

a-1)

Year

Field 1 Field 2 Field 3 Field 4 Field 5

Figure 1-2 A chart of previous crop yields helps to indicate soil fertility changes in aparticular field. Soil fertility is probably declining in Field 3 but is stable in Field 1. Thisprobably means that either Field 1 is better managed or that the native soil is more fertile inField 3.

22

Table 1.3a Examples of open and closed questions.

epyT noitseuQ rewsnaelbissoP

nepOrofdnaleraperpuoywohebircseD

.gnitnalpneht,deraelcsawdnalehttsriF

.detnalpneht,dehguolp

desolC ?gnitnalprofdnalehteraperpuoydiD !)onro(seY

Table 1.3b Examples of questions to ask households to learn about farmer knowledge tobetter understand the soil fertility management of the farm.

snoitseuQebnacnoitamrofnisihtwoH

desu

?sdleifruoyfosutatserunetdnalehtsitahW

siremrafehthcumwohetacidniyaMytilitrefliosnitsevniotgnilliw

tnanetfiylekilssel(tnemeganam.)remraf

?liosruoyfoseitreporproop/doogeratahW .liosdnalpu,dicasiliosfiyfitnedI

ruoyseodwoH ytilitreflios rehtohtiwerapmoc.yhwnialpxE?noiger/egallivehtnismraf

.ytilitreffolevellarenegyfitnedI

rofdeenatuohtiwerehtsebworgsporctahW?rezilitrefartxe

.ytilitreffolevellarenegyfitnedI

ehtfostrapnoylnoworgsporcralucitrapoD?yhW.dleif

.dleifafosaeradoogdnaroopyfitnedI

ro,desaerced,desaercniytilitrefliosehtsaH?sihtwonkuoyodwoH.emasehtdeyats

erasecitcarptnerrucfiyfitnedI.ytilitrefgniniatniam

dnanoisoreliostneverpotoduoyodtahW?ffonurretawecafrus

nactifidnamelborpasisihtfiyfitnedI.devorpmieb

?yhW?ytilitrefliosevorpmiotoduoyodtahW .koobdnahniselpicnirphtiwerapmoC

liosesaercedknihtuoyodsecitcarptahW?yhW?ytilitref

nidebircsedselpicnirphtiwerapmoC.koobdnahsiht

Step 2.6 Evaluate current soil fertilitypractices: a checklist

After determining whether or not there are anynutrient deficiencies in the field, use a checklistto assess the soil fertility managementpractices of a particular household (Table 1-7). This information will be helpful in identifying

possible improvements to the farmers soilfertility management practices.

Step 2.7 Evaluate the information andprovide a diagnosis

Use the checklist in Table 1-8 to organize theinformation you have collected related to

23

specific nutrients. Try to identify the nutrientwhose management most needs to beimproved.

Table 1-9 summarizes your investigation. First,write down the nutrient that you think mostneeds to be improved. Next, answer thequestions that follow with either a YES or NO(these should be based your answers in Table1-7). When this table is complete, you will haveidentified a nutrient which needs improvement

Table 1-4a This example shows how to organise data to compare crop yields from a farmover time and with farms in the surrounding area.

snoitavresbOemanporC

)tnecertsom=4(

noitanalpxE

ecneuqesporC 1 2 3 4

seicepsporC M S M M

fosdleiyehterewtahW?)ah/t(porcs'remrafeht

6 1 5 4

:seicepsporcralucitraparoFnaemdluocsdleiygnisaerced

gnisaercni;ytilitrefliosgninilcedliosgnisaercninaemdluocsdleiy

.ytilitref

ybdetceffaporcehtsaW,thguord,tsep,esaesid

rehtoro,dnatsroop?smelborp

oN oN oN oNniamehtebtonyamytilitreflioS1fisdleiyporcgnitceffarotcaf

.derruccosrotcafesehtfo

deredisnoceratahWrofsdleiydoog,egareva

aeraehtniporcsiht?)ah/t(

4 1 4 4,egarevanahtsselerasdleiyfI

lios,aeraehtrofsdleiydoog.ylekilerasmelborpytilitref

naebyos=S;eziam=M

Table 1-4b Use this chart to help interpret information gathered from Table 1.04a.

noitautistneserP:eraporcralucitrapamorfsdleiY

gnisaerceD gnisaercnIehtnahtsselerasdleiY

ehtrofsdleiydoog,egareva.noiger

smelborpytilitreflioSroopdna

.tnemeganam

liosebtonyamroyamerehTliosnehwnevesmelborpytilitref

.doogsitnemeganamytilitref

regralroralimiserasdleiYrofsdleiydoog,egarevanaht

.noigeremaseht

ytilitrefliosrojamoNliosrooP.smelborp

.tnemeganamytilitref

doogdnaytilitrefliosrooprehtiEliosdoogrotnemeganam

.tnemeganamroopdnaytilitref

in its management, as wells as some othermanagement practices that can be improved.

Step 3 Make recommendationsfor improvements

Step 3.1 Suggest some initialrecommendations

The initial recommendations for improvementsto the farmer s soil fertility managementdepends on the various factors: previous

24

snoitiddatneirtuNahgk 1-

aerU N PST P lCK K

rezilitreflarenimsA

eziaM1 521 85 05 32 0 0

tundnuorG2 52 21 05 32 0 0

erunamdraymrafsA

eziaM3 8 2 8

tundnuorG4 0 0 0

latot-buS a )4+3+2+1( 86 84 8

sessoldetamitsE b afo%52 71 afo%0 21 afo%01 1

latoT A (a - b) 15 63 7

lavomertneirtuN

porCdleiY

aht( 1- )tcudorP

eziaM 5.2niarg)a 04 7 01

sevael+sklats)b 52 4 23

dnuorGtun

0.1niarg)c 72 3 91

sevael+smets)d 0 0 0

latoT B 29 41 16

)B-A(ecnalaB 14- 22 45-

Table 1-5 A nutrient budget for a farmer who planted a crop of maize followed by ground-nut in a 1-ha field for one year.

Table 1-6 Some conditions where nutrients may limit crop growth in acid, upland soils.

tneirtuN gnitimilsemocebtneirtunerehwsnoitidnoCP .rezilitrefPfostnuomaegraldeviecertonsahtahtliosdnalpu,dicaynA

N,wolsisutatsMOSnehw,deilppaneebevahwartsfostnuomaegralnehW

.nworgera)ecir,eziam,.g.e(sporcgnixifN-non,gnidnamed-Nhgihnehw

KfonoitiddaonroelttilhtiwsnosaeslarevesrofdepporcneebsahliosanehW

otdenrutertoneraseudiserporcnehwylidaereromsruccosihT.rezilitrefK.lioseht

gM .KrofsA

Stoneraslairetamgniniatnoc-Snehw,denrutertoneraseudiserporcnehW

.)etimolod,etireseik,etaflusmuinomma,.g.e(deilppa

aC .sliosdicanonworgstunaepninoitamroftunstimilyltsoM

25

diagnosis process, how much time the farmeris willing to invest, labor, and capital, and onthe relationship between the farmer and theextension worker. Because most uplandfarmers are poor, it may be most appropriatefor the extension worker to suggest small,incremental changes for the farmer to test.Recommendations can be drawn up toimprove five major aspects of soil fertilitymanagement. These five points are listed inorder of the difficulty involved in changing thefarmer s practice (Table 1-10). Therecommendations may not always result inincreased production in the short term, but they

may show the farmer how to save time andcosts by changing management practices.

Important aspects

Other important aspects of soil fertilitymanagement are listed below. Although thishandbook deals mainly with the managementof mineral and organic fertilizer materials, anunderstanding of these aspects is importantas they are part of an integrated approach tonutrient management.

Plate 1-3

Check for indicator plantsand nutrient deficiencysymptoms:

a) Potassium deficiency incover plant (Puerariaphaseoloides).

b) Phosphorus deficiencyin maize.

c) A normal maize leaf(upper) compared withpotassium deficient (middle)and phosphorus deficient(lower) leaves.

d) Use a corn doctor sheetto identify nutrient deficiencyand disease symptoms.

a b

c

d

26

ecitcarP oN/seY noitceS

noitazilitreffognimiT

?emittcerrocehttadeilpparezilitrefsI 22-3elbaT,9-3

?erutsiomliostneiciffussierehtnehwdeilpparezilitrefsI 8-2

dohtemnoitacilpparezilitreF

?liosehtnidetaroprocnirezilitrefsI 8-2

?enoztoortnalpporcehtraendecalprezilitrefsI 8-2

?gnildeesro/dnadeesehtegamadotylekilrezilitrefsI 8-2

?deximgniebsrezilitrefelbitapmocnierA 01-3

noitazilitrefdecnalaB

?deilppatneirtuntneicifedtsomehtsI 7-2

tnemeganamlairetamcinagrO

?liosehtotdenruterseudiserporcerA 8-2,4-2

?dleifehtrevoylnevedaerpshsa/seudisererA 8-2,4-2

nworgsawtahtnoitategevnodefgnieberakcotsevilfI?dleifehtotdenrutergnieberunamehtsi,dleifsihtno

8-2,4-2

?dleifehtotdeilppaerunamlaminasI 8-2,4-2

?ylreporpderotserunamlaminasI 8-2

etarnoitacilpparezilitreF

?dewollofgniebsetarnoitacilppadednemmocererA 12-3,2-3

secitcarprehtO

?dellatsnineebserusaemnoitavresnocliosevaH 01-2

?putliubgniebytilitrefliossI 7-2

?detpodaneebytilitrefliosniatniamotsecitcarpevaH 7-2

?dleifmrafdnalpuehtotnidetargetnislaminaerA 8-2,6-2,4-2

?dleifmrafdnalpuehtnidetargetniseerterA-3elbaT,9-2,5-2

52

?dleifmrafdnalpuehtotnidetargetnisemugelerA 52-3elbaT,9-2

Table 1-7 Use this checklist to identify possible improvements to the farmers soil fertilitymanagement practices. Look for more information in Part 2 Sections or Part 3 Tables thatare shown in the last column.

Mixed tree-crop-livestock systems (Part2-6)Livestock and trees can both intensify landuseand may provide income stability to a foodcrop-

based upland farming system.

27

Cropping patterns, rotations, improvedfallows (Part 2-7)Important strategies include changing the cropto suit the soil, not vice versa;residue utilizationto reduce fertilizer costs; using rotations tobreak disease and pest cycles; and short-termsoil fertility improvement by the use ofimproved short-term fallows.

Introduction or improvement of legumes(Part 2-9)Introducing legume species or improving theperformance of legumes already present in thefarming system may reduce N fertilizationcosts. However, the technology (e.g.,rhizobium inoculation, introduction of improvedvarieties) is often not available to farmers.

Soil and water conservation (Part 2-10)Unless soil and water conservation measuresare introduced, attempts to improve to soilfertility may be wasted due to the loss ofnutrients by erosion and leaching. It is oftendifficult to convince farmers to adopt soil andconservation methods as short-term economicreturns are small. In addition, farmers willalways be reluctant to introduce soil and waterconservation practices unless they result inincreased crop yields and farm income. Forthis reason, soil conservation must always beintroduced together with soil fertilityimprovement, and vice versa.

� Example 1. Where livestock have beenintegrated into the farming system,farmers are more likely to plant forageplants along contour terraces.

� Example 2. Farmers may be convincedto plant rubber along contours because itreduces the amount of labour required fortapping.

� Example 3. Soil P deficiency must becorrected before improved fallows usinglegume cover plants produce asatisfactory effect on soil fertility.

3.2 Select a recommendation

Some aspects that need to be consideredwhen providing recommendations are listedin Part 2-7.

After discussing some of your initialrecommendations with the household, askthem to select up to four recommendations thatthey might like to test. Make a table similar toTable 1-11 and list down the selectedrecommendations. Next, ask the household torate how easy or hard it would be to adoptthat recommendation on a large scale (1 ha),based on capital inputs, labor inputs, technicalfeasibility/difficulty, and social considerations.In the example shown in Table 1-11, eachrecommendation has a major difficulty (hard).A lot of capital is required to follow therecommended dose, much labor is requiredto return the manure to the field, and farmersin the area never incorporate mineral fertilizer(social aspect). Rather than conclude thatnone of these recommendations can be tested,you and the household are challenged to comeup with alternatives, such as an increasing inthe fertilizer rate rather than applying therecommended rate; or substituting someanimal manure for mineral fertilizer.

Step 4 Test, evaluate and follow-up the recommendations

Step 4.1 Test the recommendation on-farmMajor principles for conducting field tests:

� Together, the farmer and extensionworker draw up a plan and decide whatneeds to be tested.

� Simple tests are implemented tocompare improved soil fertilitymanagement practices with the farmerspractice.

The improved practice should have thepotential to increase income or reduce costsby a significant margin to justify carrying outthe investigation. Examples include:

� Increasing yield by improving the balancebetween nutrients. Fertilizer costs remainthe same but yield is increased.

� Replenishment of soil P by using a largeone-off application of rock phosphate

28

airetirC oN/seY

ycneicifedP

?tneserpsmotpmysycneicifedtneirtunPerA

t1,.g.e(sraeyeviftsapehtnienodneebevahPfosnoitacilppaegraloNah 1- ?)raeyrepPST/63-PSgk003nahterom,etahpsohpkcor

?deilppasinahtdevomersiPerometacidnitegdubtneirtunehtseoD

?noigerehtnisdleiydoog,egarevanahtrewolerasdleiyporcerA

?5.5<HpliosehtsI

ycneicifedgMro/dnaK

?tneserpsmotpmysycneicifedtneirtungMro/dnaKerA

?dleifehtotdenruterylnevetonrodevomeryllausueudiserporcehtsI

?sraeyynamrofdepporcneebsahdleifehtsaH

?lavomergMro/dnaKetacidnitegdubtneirtunehtseoD

?gninilcedylidaetsneebsdleiyporcevaH

ycneicifedN

?tneserpsmotpmysycneicifedtneirtunNerA

?lavomerNsetacidnitegdubtneirtunehtseoD

?detnalpyllaususporcemugel-nonerA

?noigerehtnisdleiydoog,egarevanahtrewolsdleiyporcerA

Table 1-8 Use the table to identify possible nutrient problems. The more times you answeryes for a nutrient, the more likely that its management needs to be improved. Select the 1 or2 nutrients that need improved management and put these into Table 1-9.

� Increasing the amount of N and Kfertilizer applied to crops planted in soilwhere P has been replenished.

� Reducing N losses by incorporating Nfertilizer in the soil. In this way a smalleramount of N fertilizer results in the sameor a larger yield compared with surface-applied fertilizer.

Make the plots large enough to provideconvincing evidence to the farmer on the effectof the treatments. As a guideline, test plotsshould be 100—1,000 m2. (e.g., plot sizes of10 m x 10 m to 25 m x 40 m)

Choosing treatmentsDiscuss the recommendations with the farmer.Explain the expected effect of the differenttreatments. Discuss the requirement foradditional inputs and the comparative cost ofeach management practice. For example,additional capital may be needed to purchasemore fertilizer, or additional labour may berequired to incorporate fertilizer and lime (Step3.2).

When selecting a recommendation to test, tryto keep it simple enough that it is feasible forthe farmer to adopt if successful. See Part 3-6for some examples of treatments to test. The

29

farmers practice is always included to comparewith the treatment plots.

If a farmer is planting a 1 ha field, then selecttwo areas each of 100 m2. In one plot carryout the recommended practice. In the rest ofthe field (which includes the other plot), thefarmer simply continues his/her normalpractice. The yield in the two windows is thebasis for comparison (Figure 1-3).

Selecting a test locationSelecting a proper test location ensures thatdifferences in crop yield between the plots isdue to the treatments and not because of soilor location differences. The two plots shouldtherefore be as similar as possible. Forexample, do not site one plot at the bottom ofa hill and another at the top of a hill, or oneplot on an area that was often fertilized in thepast and another plot on an area that has neverbeen fertilized (Figure 1-3).

Applying the treatmentsBoth plots should receive the samemanagement except for the additional aspectsincluded in the improved soil fertilitymanagement practice. All plots should beplanted at the same time, and all maintenanceactivities carried out at the same time in eachplot. However, improved soil fertility mayshorten the period to crop maturity and resultin differences between the treatments inharvest date.

Step 4.2 Monitor and evaluate the testwith the farmerTogether, the extension worker and the farmerchoose objectively verifiable indicators tomonitor and evaluate the plots. Someexamples of indicators are listed in Table 1-12, but the farmer may add others more suitedto local conditions.

tneirtuN

tnemevorpmitnemeganamsdeentsomtahttneirtuN

noitseuqsihtrewsnaota8-1elbaTesU

oN/seY

?devorpmiebgnimitrezilitrefnaC

?devorpmiebdohtemnoitacilpparezilitrefehtnaC

?devorpmiebecnalabrezilitrefnaC

?devorpmiebtnemeganamlairetamcinagronaC

?devorpmiebesodrezilitrefehtnaC

(devorpmiebnactahtecitcarprehtoynaerehtsI erehtresni )

?_________________________________________

(devorpmiebnactahtecitcarprehtoynaerehtsI erehtresni )

?_________________________________________

snoitseuqevobaehtrewsnaot7-1elbaTesU

Table 1-9 Use this table to summarize your investigation. Use Table 1-8 to determinewhich nutrient, if any, needs improved management and put this in the upper part of thistable. Then use table 1-7 to fill in the lower part of this table. Use all of this information tostart developing recommendations with the household to improve their soil fertilitymanagement.

30

melborP noitadnemmoceR

1 evorpmI .noitacilpparezilitreffognimit

srezilitrefylppasremraF.emitgnorwehtta

.gnitnalptasrezilitrefKdnaPylppA

porcotgnidroccasnoitacilppatilpsnisrezilitrefNylppA.egatshtworg

2 evorpmI .noitacilpparezilitreffodohtem

tonerasremraF.rezilitrefehtgnitaroprocni

noitazilatalovdnagnihcaelecuderotrezilitrefetaroprocnI.sessol

.enoztoorporcehtraensrezilitrefylppA

3 ecudortnI .noitazilitrefdecnalab

egralylppasremraFtubrezilitrefNfostnuoma

KdnaPtneiciffusni.rezilitref

decnalabnisrezilitrefNhtiwsrezilitrefKdnaPylppAsisrezilitreffotsocdnaytitnauqlatot(snoitacilppa

.)desaercni

ehtesaercnidnadeilpparezilitrefNfotnuomaehtecudeRtsocdnaytitnauqlatot(deilpparezilitrefPdnaKfotnuoma

.emasehrtsniamerrezilitreffo

hsinelperotrezilitrefPfonoitacilppaemit-enoegralaylppA.tnetnocPlios

4 evorpmI .tnemeganamlairetamcinagro

wartsecirsnrubremraFehtnipaehegralenoni

.dleifehtforenroc

.gninruberofebwartsehtdaerpS

.gninruberofebdleifelohwehtrevohsaehtdaerpS

evisseccusnidleifehtfostraptnereffidninrubotegnarrA.snosaes

devomereraseudiseRdeefotdleifehtmorf

.elttacs'remraf.dleifehtoterunamlaminanruteR

5 ezimitpO .esurezilitrefwoleberasetarrezilitreF.mumitpocimonoceeht

.stnemercninideilpparezilitreffotnuomalatotehtesaercnI

Table 1-10 Discuss and summarize your findings with the family mebers. Together makerecommendations to improve five aspects of soil fertility management. Some examples arelisted in the table.

Implementing and monitoring the fieldtestThe extension worker should visit the test siteand guide the farmer at the following stages:

� Plot layout - make sure that plots arelocated and laid out correctly

� Treatment application - make sure thatthe treatments are properly implementedaccording to plan in each plot (Plate 1-5).

� Crop growth period - one visit during thevegetative phase or at flowering todiscuss any obvious treatmentdifferences or any problems (e.g., pest

31

and disease) that may affect the results(Plate 1-6).

� Harvest time - to help the farmer evaluatethe final results and take samples foryield comparison, or partial budgetanalysis (Step 4.4).

Evaluating the field testEvaluation ranges from a simple comparisonto determine whether the recommendedpractice was effective or not, based on visualobservations, to more complete yield recordingin each of the treatments (Plate 1-4). Someform of economic analysis is essential if thefarmer is to be convinced that increased yieldsand costs result in greater profits (and no

significant increase in risk). It may be usefulto involve neighboring farmers in themonitoring and evaluation of the field test.

Step 4.3 Yield Sampling

There are several sampling methods forcomparing yields in the different treatments(Part 3-2 and 3-3).

Step 4.4 Partial budget analysisA partial budget analysis allows the farmer tocompare the returns to any investment inlabour, capital, or other resources. Only coststhat are different in the two treatments areincluded (hence the term partial budget).

The additional income the farmer gets fromapplying the recommended dose of fertilizerto 1 ha of groundnut is shown in Table 1-13.

ebnacnoitadnemmocerahcihwhtiwesaeevitaleRsnoitaredisnocsuoiravnodesabdetpoda

snoitadnemmoceR latipaC robaL lacinhceT laicoS

rezilitrefetaroprocnI ysaE draH ysaE draH

esodrezilitrefdednemmocerylppA draH ysaE ysaE ysaE

llatsehtmorferunamlaminanruteRdleifehtot

ysaE draH ysaE draH

Table 1-11 Based on the example shown in this table, the household makes an analysis ofsome of the factors that can affect the testing and adoption of a recommendation. Rate eachrecommendation according to how easy it would be to implement on a large scale (e.g., 1ha) based on the capital required, labor required, technical constraints, and socialconsiderations.

Plate 1-4

Regularly monitor andevaluate the field test withthe farmer.

32

The farmer needs to increase the fertilizer doseby a total of 200 kg, which requires anadditional man-day to spread the fertilizer.Together, this cost an additional $33 ha-1. Butbased on the field test, the farmer gets a yieldincrease of 0.75 t groundnut ha-1, which canbe sold for an additional $47.50. Thus, thefarmer gets $47.50 ha-1 for an additionalinvestment of $33 ha-1, equivalent to a netincrease in profits of $ 14.50

Discuss the possible residual effects ofdifferent aspects of the treatments on futurecrop productivity during the discussion with thefarmer.

Step 4.5 Follow-up the field test with thefarmer

What to do with the results: A very importantpart of the process is the follow-up action afterthe field test has been completed.

Below are some suggestions on what to dodepending on the test results:

1 The farmer practice is better (in terms ofyield or return per unit input), or there isno difference, or if something went wrongwith the test.

Some possible explanations (which shouldbe discussed with the farmer) include:

� Another factor (pest, drought) maskedthe difference between thetreatments.

� Plots were not properly selected (e.g.,the farmers practice was implementedon more fertile soil than the improvedsoil fertility management practice).

� The recommended practice does notproduce a short-term benefit. Somesoil management practices onlyprovide an increase yield and incomeover a period of several croppingseasons.

The extension worker and farmer shouldevaluate whether the recommendedpractice was suitable.

In some cases a difference may not beexpected (e.g., a demonstration to showthat the same economic return can beachieved with less costly soil fertilitypractices).

2 The farmer practice is actually better thenthe recommended practice.

In all cases, the farmer and extensionworker should discuss the implementationof a second test in the following season,after taking into account the evaluation ofthe first test.

3 The recommended practice is better.

The farmer determines whether or not toadopt the practice in its original or amodified form. It may be advisable to runthe test for a second season to confirm thatthe technology is sufficiently robust toproduce good results under differentgrowing conditions and seasons.

Step 4.6 Disseminate the field testresults

If positive results are obtained, the farmer andextension worker may wish to share the results

Figure 1-3

Design a simple, inexpensivefield test with the farmer totest a recommendation. Inthis example, the effect ofincorporating fertilzer on cropyield is under test.

33

ecitcarpdednemmocermorfemocnilanoitiddA $

ecitcarpdednemmoceR t06$@tudnuorgt52.1 1- 00.57

ecitcarpremraF t55$@tundnuorgt5.0 1- 05.72

)A(emocnilanoitiddateN 05.74

ecitcarpdednemmocermorfemocnilanoitiddA

slairetaM,PSTgk521,aerugk52:deriuqerrezilitreflanoitiddA

gk41.0$@lCKgk05dna 1- 00.82

ruobaL yad-nam5$@gnidaerpsrofrobalyad-nam1 1- 00.5

)B(stsoclanoitiddalatoT 00.33

)B-A(ecitcarpdednemmocergnisumorfstsoclanoitiddarevonigraM 05.41

Table 1-13 Example of a partial budget analysis for comparing the recommended fartilizerdose with the farmers practice for groundnut.

dleiytsevraH stupnifotsoC thguordotecnareloT

ruoloctnalP emocniteN niargforuovalF

thgiehtnalP tnemeriuqerruobaL ssamoibfotnuomA

tnalp/sdopforebmuN sevaelfoeziS tsevrahotemiT

liosfolevelerutsioM tsevrahporcfoesaE ssollioS

Table 1-12 These are examples of indicators to evaluate simple field tests.

Plate 1-5

The improved treatment (left)compared to the control(right) in an on-farm trial totest the addition of fertilizersP and lime.

with other farmers in the village (Plate 1-6). Thisis always more effective where the neighboringfarmers have been fully briefed from the outseton the aims of the test.

34

Plate 1-6

a) Share the field resultswith other farmers.

b) With improved soil fertility,unproductive alang-alang(right) has been transformedinto productive land (left).

a

b

35

In this section

2-1 Chemical Characteristics of Acid, Upland Soils

2-2 Physical Characteristics of Acid, Upland Soils

2-3 Biological Characteristics of Acid, Upland Soils

2-4 Causes of Soil Fertility Problems in the Uplands

2-5 Plant Nutrition and Nutrient Cycles

2-6 Nutrient Requirements of Integrated Upland Systems

2-7 Soil Fertility Management

2-8 Nutrient Sources

2-9 Biological Soil Fertility Management

2-10 Indirect Management Effects on Soil Fertility

Part 2Principles and methods

36

Plate 2-1

Upland soils are usually lowin inherent fertility. Nutrientsneed to be added to achieveproductive agriculturalsystems

of Indonesia usually range from pH 4.0 to 5.5.Many crops are adapted to acid soils and growwell in low pH soils (pH 4.5-5.5).

A simple, accurate way to measure soil pH isto use a pH meter kit. A small amount of soil isplaced in the receptacle. Indicator fluid isadded and gently agitated. Indicator fluid isallowed to run along the groove and the soilpH is read off the scale (Plate 1-1a).

Low soil pH does not limit crop growth, butsoil pH influences other factors that can affectcrop growth (Figure 2-1 and Table 2-2). LowpH reduces the availability of some nutrientsto plants, reduces biological activity, andincreases the likelihood of Al toxicity (Table 3-5). Applying large amounts of acidifying Nfertilizers (e.g., ammonium sulphate)decreases the soil pH.

There are a number of benefits from increasingsoil pH (Figure 2.1):

� Al, Mn, and Fe toxicity are decreased,

� biological activity is increased,

� the soil can store and make morenutrients available to plants, and

� P-fixation is decreased.

Aluminium toxicity

Aluminium is present in all soils and in highly-weathered soils it may only become toxic when

2-1 Chemical characteristics ofacid upland soils

Acid, upland soils are usually low fertility status(Plate 2-1) because of either some or all ofthe following factors:

� The soil originated from low nutrientcontent material (e.g., acid igneous rockscontain a small amount of potassium;acid volcanic rocks are poor in nutrients).

� Nutrients have been removed because ofthe long-term effect of weathering underhigh rainfall and temperature, resulting inlow soil pH and poor nutrient status.

� Soils have been depleted of nutrients dueto exploitative agriculture (e.g., slash andburn agriculture, continuous rotationswithout the use of mineral fertilizer,removal of crop residues, unbalancedfertilizer use).

Critical values for soil chemical properties for45 upland crops are shown in Table 3-6. Theeffects of nutrient deficiencies on crop growthare shown in Table 2-1.

Soil acidity

Soil pH is a measure of soil acidity. A soil pHof 7.0 is termed neutral, soil pH <7.0 is acidand pH >7 is alkaline. The pH of most soilsranges from about 4 to 9. Acid, upland soils

37

the pH is less than 5.5. However, not all highly-weathered soils are affected by Al tocitity.

Usually, the main reason for increasing the pHin an acid soil is to reduce Al toxicity. Al toxicityaffects crop growth mainly by reducing rootgrowth, and a common symptom of Al toxicityis stunted roots. Some crops, like maize andsoybean, are more susceptible to Al toxicitythan others (Plate 2-2a). Al toxicity is moreoften a problem in the subsoil (i.e., soil depthof >20 cm). Crop roots may grow properly inthe topsoil, but cannot scavenge for water inthe subsoil because of Al-toxicity. During adry period (sometimes only a few days inlength), plants cannot absorb sufficient water(shown by leaf rolling in maize) because thetopsoil has dried out and the roots cannotreach the water that may be available in thesubsoil (Plate 2-2b).

Where Al toxicity is a problem, one or both ofthe following strategies may be used:

Figure 2-1

Soil pH influences soilnutrient availability to plantsand soil micro-organismactivity.

1 Change the crop

Some crops, (e.g., cassava), are quitetolerant of Al-toxicity while others, (e.g.,soybean), are very sensitive (a summaryof this is provided in Table 3-5). Even withina species, varieties differ in their toleranceof Al-toxicity. Unless Al toxicity is corrected,the farmer s choice of crops (and thereforescope for farming systems development)is severely constrained.

2 Modify the soil

Modifying the soil is usually more costlythan changing the crop, but it providesadditional benefits. Apply organic materialsto reduce Al-toxicity in the subsequentcropping season. About 1 t of organicmaterial (fresh weight) is equivalent to theeffect of about 100 kg of lime. Becauseorganic materials usually only reduce Al-toxicity for one or two seasons, freshorganic material must be added regularly.

38

Table 2-1 Common nutrient deficiencies/toxicities in acid, upland soils and effects on cropgrowth.

citsiretcarahC htworgporcnotceffE

lioswoL)P(surohpsohp

sutats

sutats-Pwolnillewworgtonod,semugelyllaicepse,sporcynaMrezilitreflarenimafomrofehtnideddaebtsumP,yllausU.slios

.etahpsohpkcorroPSTsahcusNlacigoloibnoylerotdennalperasmetsysgnipporcerehW 2

porcotNfoylppusehtstimilyltceridninetfoycneicifedP,noitaxif.)2.9traP(stnalp

negortinlioswoLsutats)N(

rettamcinagroliosfotnuomaehtnosdnepedylppusNliosehTliosehttahtNeromeht,MOSfotnuomaehtretaergehT.)MOS(

.stnalpotylppusnac,.g.e(stnalpemugel-nonllafohtworgehtsecuderNlioswoL

stupniNemosmorftifeneb,revewoh,sporcllatsomlA.)slaerec.)51-3elbaT(

lioswoL)K(muissatop

sutats

neebevahtahtsliosnitneicifedsemocebyllausumuissatoPsrezilitrefKfoesuehttuohtiwsraeyrosnosaeslarevesrofdepporc

.lCKsahcusnideniatnocsitnalpehtybpunekatKehtfotsom,sporcynamnI

ruccootylekileromsiycneicifedKeroferehtdnaseudiserporc.)4.4traP(dleifehtmorfdevomereraseudiserporcerehw

muiclaclioswoLsutats)aC(

,.g.e(sporcemostub,sliossutatsaCwolniworgnacsporcynaM-aCwolnisllehs/sdopdepolevedylreporpmroftonod)tundnuorg

.sliossutatslarutlucirgasahcusslairetamgnimilnideilppayllaususimuiclaC

.)2.1traP(etimolodroeticlac,emil

lioswoL)gM(muisengam

sutats

neebevahtahtsliosnimelborpasemocebylnoyllausumuisengaMgMfonoitiddaehttuohtiwsraeyrosnosaeslarevesrofdepporc

.)etireseik,etimolod,.g.e(srezilitrefdevomereraseudiserporcerehwnommoceromsiycneicifedgM

.)4.4traP(dleifehtmorf

lioswoLtneirtunorcim,B,nZ(sutats

).cte

nitnalpehtybderiuqereratahtstneirtunerastneirtunorciM.seititnauqllamsylevitaler

tcerrocottnatropmieromemocebyllaususeicneicifedtneirtunorciMehttuohtiwsraeylarevesrofdepporcylevisnetnineebsahdleifafi

.)3traP(stneirtunorcimfonoitidda

Alternatively, apply calcitic or dolomitic lime,which can reduce Al-toxicity for up to 5 yearsif the amount applied is large (>3 t ha-1 limingmaterial). The application of 1 t ha-1 rock

phosphate may have a small liming effect byincreasing the soil pH by about 0.2—0.3 units.

The best method to decide how much lime toapply is first to determine the sensitivity of the

39

crop and then measure the soil Al-saturationwith a soil test.

Soil testing for Al saturation may not alwaysbe available or affordable so it may benecessary to make an approximation asfollows:

� If the soil pH is above 5.5, then lime isprobably not needed.

� If the pH is below 5.5, then some limemay be needed.

The guidelines in Table 2.3 should be usedwith caution because other factors such assoil type and the choice of crop will affect thelime requirement.

These guidelines can be used to select a limedose that can be tested in a simple field trialusing small 100-1000 m2 plots (Step 4.1). Forexample, Table 2-3 shows that if the soil pH is4.5, then the lime requirement to reduce Al

saturation to 30—40% is about 1—3 t lime ha-1.Approximate critical Al saturation levels forvarious crops are given in Table 3-5. A simplefield trial could be used to test the effects of 3t ha-1 lime compared to a plot where lime wasnot applied. The farmer may also decide to addanother treatment of 1.5 t ha-1 lime to determinewhether the economic return would be greaterwith a smaller application of lime.

Low phosphorus availability

Acid, upland soils are not only low in nativesoil P, but they also can fix P that is added tothe soils in fertilizers. P-fixation is a chemicalprocess in which P added in fertilizer materialsis fixed by the soil and becomes unavailableor only slowly available for plant uptake. Cropsdiffer in their tolerance of low soil P fertilitystatus (Table 3-4). P fixation is mainly aproblem in volcanic soils, and in some acid,upland soils with a clayey texture that contain

Table 2-2

rotcaF tceffE

yticixotlA .)1-2erugiF(HpgnisaercnihtiwsesaercedyticixotlA

ytilibaliavaP .0.7–5.5HpmorftsetaergsiytilibaliavaP

ytilibaliavatneirtunorciMllamsnideriuqerstneirtun(

)stnalpybstnuoma

Hpmorfelbaliavaeromera,oMtpecxe,stneirtunorcimllA.)egnarsihtnideziminimsiyticixoteFdnanM(0.6–5.5

yticapacegnahcxenoitaCniaterotliosafoytilibaeht()K,gM,aCsahcussnoitac

gnisaercnihtiwsesaercniyticapacegnahcxenoitacehTelbasiliosehtsnaemsihT.sliosderehtaewylhgihniHptsolebesiwrehtothgimhcihw,K,gM,aCeromniaterot

.gnihcaelot

eht(noitazilarenimnegortiNcinagromorfNfoesaeler)smrofelbaliavatnalpotni

tsebnoitcnufnoitazilarenimNrofderiuqersmsinagrolioS.5.6–5.5Hpliosta

fonoisrevnoceht(noitaxif-NotnierehpsomtaehtmorfN

ybdesuebnactahtsmrof)stnalp

sselnoitcnufdnaruccootylekilsseleraseludongnixif-N.)9-2traP(5<Hptaylevitceffe

esaesiDHpliosgnitalupinamybdellortnocebnacsesaesidemoS

gnisaercedhtiwsesaercedecnedicnibacsotatop,.g.e(.)Hp

)PR(etahpsohpkcoRnoitulossid

rofPesaelerdnaevlossidotPRrof5.5<ebtsumHplioS.)8-2traP(ekatputnalp

40

large amounts of Al and Fe oxides (in well-drained soils, Fe oxides account for theirreddish color). A large application of P fertilizeris required on these soils to overcome P-fixation such that some of the applied P isavailable for plant uptake (Plate 2-4). AlthoughTSP can be applied, rock phosphate is a moresuitable P material for acid, upland soils wherethe pH is <5.5. The acid soil helps dissolvethe rock phosphate. Because the P in rock

phosphate is only slowly available, a largeinitial application of about 1 t ha-1 is required,but the residual effect persists for several years(Part 3-8).

2-2 Physical characteristics ofacid, upland soils

When carefully cleared of their protectivenatural forest cover, the physical properties of

Table 2-3 Lime requirement for various crops at different levels of Al saturation.

niHpretaw

muinimulAnoitarutas

)SA(

hcaerottnemeriuqeremitetamixorppA

SA%02–01,naebyosrof,.g.e(

)naebgnum

SA%04–03,eziamrof,.g.e(

)tundnuorg

9.4–0.4 %03–07 ahemilt4–1 1- ahemilt3–1 1-

5.5–0.5 %0–03 ahemilt4–0 1- ahemilt5.0–0 1-

5.5> %0 ahemilt0 1- ahemilt0 1-

Plate 2-2

a) Maize roots are verysensitive to AL toxicity. Theroots on this plant arestubby, stunted anddiscoloured due to soil Altoxicity.

b) When combined withblanced fertilization, limingcan raise the productivity ofcrops sensitive to low pH andAl toxicity. Note the poorgrowth of the unlimed plot inthe foreground.

c) The poor growth ofmaize plants in the Limeonly plot show that N, P andK nutrients must be appliedin addition to lime to achievesatisfactory yields.

a

b c

41

most acid, upland soil types are suitable forcrop production (Plate 2-4d). However, theirphysical properties are easily destroyed byimproper cultivation, especially practices thatresult in the loss of topsoil due to erosion (Plate

2-4e), surface runoff or excessive mechanicalmixing of subsoil and topsoil. Each aspect ofsoil physical fertility has different effects oncrop growth (Table 2-4). The different termsare defined in Table 3-31.

Plate 2-3

a) A large application ofreactive rock phosphate (90—130 kg P ha-1) is required toovercome low soil P status.

b) The rock phosphateshould, if possible, beploughed into the soil toreduce losses of P fertilizerfrom surface runoff anderosion.

c) Excellent groundnutgrowth can be achieved afterP-deficiency has beencorrected by an applicaton of1 t rock phosphate ha-1 (rightside of photo). Soilconservation measures mustalso be installed to minimizethe loss of added fertilizer P,and improved germplasmshould be used to takeadvantage of the increasedsoil fertility.

d) Upland soils usuallyhave good physicalproperties, as shown by thistopsoil where the clayparticles have aggregatedinto larger particles. Waterinfiltration is more rapid inwell-aggregated soils.

e) Erosion of the topsoilexposes the clayey subsoilthat has poor physicalproperties, water infiltration islow and the soil is hard tocultivate.

a

b c

d e

42

2-3 Biological characteristics ofacid, upland soils

Soil is a living body and biological processesthat depend on an adequate population of soilinvertebrates, bacteria and fungi are vital tosoil fertility. Each particular aspect of biologicalsoil fertility has different effects on plant growth(Table 2-5).

Soil organic matter (SOM) is organic materialof biological origin found beneath the soilsurface that has partly or completelydecomposed. SOM is about 58% carbon. SOMhas a number of important functions in the soil:

� Store for N, P, S, and most micronutrients

� Contributes to the soil s capacity to retainnutrient cations (Ca, Mg, and K)

� Source of energy for microbialdecomposition of organic residues (e.g.,leaf litter, crop residues).

� Increases soil water-holding capacity

� Improves soil structure through greatersoil aggregation, resulting in more rapidwater infiltration and reduced runoff.

SOM should be distinguished from organicmaterial, which includes the above- and below-ground litter, crop residues, mulches, greenmanures, animal manures, and sewage.

Low SOM status indirectly affects crop growthin many ways. In acid, upland soils the SOMis an important source of nutrients andcontains much of the N, P and S reserves intropical soils. Therefore, if the amount of SOMis small, the stocks of these nutrients willprobably also be small.

The concentration of SOM in tropical soils isnot smaller compared with temperate soils ashas sometimes been stated. A sample of soilsfrom both temperate and tropical regionsshowed that soils in both climatic regionsaveraged 2.8% SOM in the 0-15 cm soil layer.

The greater concentration of SOM in thetopsoil is one of the main functional differencesbetween the topsoil and subsoil of many acid,upland soils.

It is very difficult to increase the amount ofSOM in the soil once SOM has been depleted.The concentration of SOM in a soil isdetermined by the amount of organic materialadded to the soil and its rate of decomposition.For example, SOM status decreases in soilsafter the rainforest cover has been removedand the land brought into agriculturalproduction (Figure 2-2). This is because theamount of organic material added to the soilis small, cultivation increases the rate of SOMdecomposition, and organic material isremoved in the harvested portion of the cropand through burning crop residues or nativevegetation (Part 2-4).

About 10 t ha-1 yr-1 organic material is addedto soils under rainforest in leaf, twig and treefall and SOM concentration is maintained in adynamic equilibrium. However, a greateramount of organic material would have to beadded to soil under annual crop productionbecause SOM losses are greater comparedto the soil under forest cover. About 10 t ha-1

yr-1 organic material is added to the soil underrubber and oil palm and this explains why SOMis maintained or even increased under theseperennial crop production systems.Management must aim to restore or maintainSOM (Table 2-6).

2-4 Causes of soil fertilityproblems in the uplands

Impact of clearing rainforests on soilfertility

The natural land cover in much of SoutheastAsia is rainforest. However, over the past 50years the population of the region has grownfrom about 180 million to over 500 millioninhabitants. Large areas of land have beencleared to meet the increased demand for food(e.g., rice, sweet potato, maize) and tradedagricultural commodities (e.g., coffee, cocoa,sugar, palm oil).

Nutrient cycling in forest systems

The paradox of luxuriant vegetation growingon infertile soils is very striking and has

43

Table 2-4 Relationships of some soil physical characteristics to the cropping environment.

citsiretcarahC tnemnorivnegnipporcehtotspihsnoitaleR

erutcurtslioSfotnemegnarraehT

regralniselcitrapliossetagerggarostinu

sliosdnalpu,dicafoedargerutcurtsgnortsotetaredomehTtrapallaftonodsetagerggarostinuregralehttahtsnaem

.ylisaestneverp,retawniarfoeganiarddoogswollacitsiretcarahcsihT

.htworgtoorporctneiciffusrofswolladna,gniggol-retawlios

erutxeTnoitroporpevitalerehT-dnasdna,tlis,yalcfo

selcitrapdezis

gnidlohretawliosregralanistlusertnetnocyalcretaergA.porcehtotytilibaliavaretawretaergdnayticapac

sitahtliosehtniPfotnuomaehtsecuderhcihw,noitaxif-P.sliosyalcnidecnuonorperomnetfosistnalpotelbaliava

htliTwohfoerusaemA

otsiliosaysaeroeohahtiwetavitluc

wolp

.edargerutcurtsliosehtotdetalerylesolcsihtliT.etavitlucotreisaeyllaususisetagerggallamssmroftahtlioS

.noitagerggaliossesaercniMOSnistnuomaegralnitneserpyllausueraeseht(sedixoeFdnalA

.etagerggaotliosplehosla)sliosdnalpudica

gnidloh-retaWyticapac

wohfoerusaemAnacliosaretawhcum

niater

notnednepedylniamsidnasliosneewtebylediwseiravsihT.erutxetlios

ydnasnahtyticapacgnidlohretawregralaevahsliosyeyalCrofretawtneiciffusdlohyamliosbusyeyalchtiwslioS.slios

elbaebtonyamstoortnalptub,sdoirepyrdgnirudhtworgtnalpporcstcirtserdnahgihsiyticixot-lAliosbusfiretawehtesuot

.)1-2traP(tnempolevedtoor

eganiarDahcihwybesaeehT

ffoniardotelbasiliossahtahtretawssecxe

liospotehtderetnereyal

gnortsriehtfoesuacebgniniard-eerferasliosdnalpudicatsoMrofskcarcdnaseropsuounitnoc,egralsedivorphcihw,erutcurts

liosotenorpsseloslaerasliosgniniard-eerF.eganiarddipar.llamssiffo-nurretawfotnuomaehtesuacebnoisore

ehtnehwderiapmiylerevesemocebyameganiard,revewoHehT.tsolneebsahliospotehtretfadesopxesiliosbusyeyalc

gnicuder,delaesylisaeeraliosbusyeyalcdesopxeniseropenif.noisorednaffonurecafrusgnisaercnidnanoitartlifniretaw

ruoloC

ro)eganiarddooggnitacidni(hsidderebyamliosbusehT.)eganiardroopgnitacidni(hsiulb,hsiyerg,hsiwolley

setacidni)gnilttom(liosbusehtnistopsderfoecneserpehTyllacidoirepsiliosbusehttahtstseggusdnaeganiardroop

.retawhtiwdetarutas

htpedlioSrosreyalkcorothtpeDhcihwwoleb,tamdilos

tonyllausunacstoorworg

02–0(reyalliospotnihtafotsisnocsliosdnalpu,laciporttsoMtnerapderehtaewforeyalpeedyrevagniylrevo)htpedmc

larevesotsretemitnecwefamorfhtpedniyravsreyaL.lairetam.sretem

fohtworgsuorogivrofyrassecensitnempolevedtoorpeeD.sporceertemos

44

sometimes led to the misconception that soilsunder tropical rainforest are very fertile. In fact,the rainforest can grow on very nutrient poorsoils because it has a closed nutrient cycle(Figure 2-3). Natural forests are not affectedby large nutrient losses through processessuch as biomass removal, leaching, or erosionthat occur in agricultural systems (Section 2-5). When rainforest plants take up nutrientsfrom the soil (or obtain them from the

Table 2-5 Effect of soil biological characteristics on crop growth.

msinagrO noitcnuF htworgporcnotcapmI

lioSsetarbetrevni

,.g.e(,smrowhtrae

)setimret

sesopmoceDskaerbdna

cinagronwodotseudiser

rehtrufebdesopmoced

seborcimyb

stneirtungnikamybhtworgporcnotcapmievitisoP.ekatpuporcrofelbaliava

cinagronideniatnoc)PdnaNyllaicepse(stneirtuN.stnalpotelbaliavaeromemoceblairetam

otrefer,gnihclumyb,.g.e(ecafrusliosehtgnirevoC.ytivitcaetarbetrevnisesaercni)8-2traP

airetcaB

strevnoCelbaliavanu

otnistneirtunelbaliava

smrof

otelbaliavasmrofotniNfonoisrevnoc(noitacifirtiNhserfhtiwdeilppusllewsliostsiomnitsetaergsi)stnalp

.MOSfonoitalupoprellamsadnaseicepsreweferaerehT

MOSwolnidna,saerayrdni,sliosdicaniairetcab.slios

lazihrrocyMignuf

tneirtuNekatpu

erastoornehwdesaercnisisliosPwolniekatpuP.ignuflazihrrocymhtiwdetcefni

secnahnesnoitatorporcdnaegallitmuminiM.snoitaicossaazihrrocym

Pnehwsseldna,sliosPwolniretaergnetfosinoitcefnI.deilppaerasrezilitref

morftifenebotthguohteraananabdnaavassaC.noitcefnilazihrrocym

.sliosdicanievivrusazihrrocyM

airetcaBsisoibmys

noitaxif-N 9-2traP

,ignuFnoitisopmocedtoor,stcudorp

snoitercxe

liossesaercnInoitagergga

eraytilibaliavatneirtundna,noitartlifniretaw,noitareA.liosdetagergga-llewanidevorpmi

cinagroydoownwodgnikaerbroftnatropmieraignuF.seudiser

-orcimsuoiraVsmsinagro

liosnitneserp

dnasesaesiDstsep

retfasraeyliosehtniniameryamsmsinagroesaesiD.stnalpgnitcefni

snegohtap,stcesnilortnocplehyamsmsinagroemoS.sdeewdna

atmosphere), they are returned to the soilthrough leaf wash, plant death, root death, orwhen leaves, twigs and trees fall to the forestfloor and decompose. Only small amounts ofnutrients are lost through erosion because thesoil is protected by the forest canopy andleaching losses are small because of efficientnutrient recycling.

45

The litter layer on the forest floor protects thesoil surface and is itself protected from the sunand rain by the forest canopy cover. The forestfloor environment favours biological activity,resulting in the rapid decomposition and

Table 2-6 Effect of some management practices on SOM.

ecitcarP tceffE

noisoreliosecudeR .MOSfosessolsecudeR

ytisnetniegallitecudeR .noitisopmocedMOSfoetarrewolS

N/C(ytilauqeudiseR)oitar

sselera)wartsecir,.g.e(oitarN/CediwahtiwseudiseRtundnuorg,.g.e(oitarN/Cworranahtiwesohtnahtevitceffe

.MOSgniniatniamni)sevaeldesaelerdnadezidixosiseudiserNwolninobracehtfohcuM

OCsa 2 .llamseroferehtsidetaercMOSfotnuomaehtdna,

denruterseudiserporCdleifehtot

.tnemhsinelperMOSroflairetamwarsedivorPerunamlamina,kcotsevildeefotderiuqereraseudiserfI

.liosehtotdenruterebdluohs

Figure 2-02 The level of SOM is affectedby the vegatation and land use. Clearingrainforests for agriculture reduces the SOMby 30—60%. This decrease can be sloweddown or reversed by imitating some of theaspects of natural systems (e.g., protectivesoil cover, no tillage).

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10

Soi

l org

anic

mat

ter

(% v

alue

at l

and

clea

ring)

Year after land clearing

release of nutrients from dead vegetativematter. Nutrients are readily reabsorbed bythe large number of tree roots that grow in thefertile litter layer beneath the forest floor.

Once the rainforest has been removed, thedelicately balanced cycle of nutrients betweensoil and above ground vegetation as well asthe processes that prevent nutrient losses aredisturbed (Figure 2-4). Most acid upland soilscannot support agricultural cropping systemswithout the implementation of soil conservationpractices and the addition of fertilizer nutrientinputs. Some of the temporary changes thatresult from forest clearing are listed below:

� Single, large addition of nutrients to thesoil surface when the forest biomass isburned (150-250 kg N, 30-120 kg P, 300-800 kg K, 250-1000 kg Ca and 30-180 kgMg ha-1).

� A temporary increase in pH and basesaturation of the top soil.

� Very irregular distribution of nutrientsacross the soil surface as a result ofclearing and burning practices.

� Poor soil tilth following the irreversibledehydration of soil particles because ofhigh temperatures during burning.

� Short-term decrease followed by a large,sudden, increase in microbial activity.

� Loss of protective forest canopy.

46

Figure 2-3

Forests are able to grow onnutrient-poor soils in partbecause of their efficientnutrient cycling systems.

Green lines represent internalcycling in the soil-vegetation system.Blue lines represent additions to thesystem. Red lines indicate lossesfrom the system. The width of thelines indicates the amount ofnutrients moved).In virgin forests, the losses are smalland balanced by also smalladditions.

Figure 2-4

Replacing rainforests withagricultural systems resultsin less efficient nutrientcycling and large losses ofboth above- and below-ground nutrients.Nutrient content is restored if theland is not disturbed by burning andallowed to return to forest cover forlong periods. With 14-year fallows,acid, upland soils may return toinitial soil fertility status. Under a 4-year fallow or continuous low-inputannual cropping, soil fertilitydecreases.

0 10 20 30 40 500

20

40

60

80

100

Soi

l fer

tility

(%

of o

rigin

al)

Years after first land clearing

14-year fallow

4-year fallow

Continuous low input cropping

� Loss of protective mulch layer on theforest floor.

� Reduced organic inputs to replenishSOM.

Permanent changes to the soil following landclearing and burning are shown in Table 2-7.

47

Nutrient cycling in agricultural systems

In many food crop agricultural systems, soillosses due to erosion, leaching, andvolatilization (losses to the atmosphere) arelarge because of the lack of soil cover. Incontrast to the forest floor, the soil surface inmost agricultural systems is periodicallyexposed and subjected to extremes of heatand moisture (Figure A-1). This reducesbiological activity and makes it difficult for plantroots to grow near the soil surface where mostof the nutrients are located.

Unlike undisturbed forests, agriculturalsystems sustain large nutrient losses due totheir removal in crop products, crop residuesand harvested biomass (Figure 2-5, Plate 2-

Table 2-7 Factors affected by clearing and burning forest.

rotcaF gniraelcerofeB gniraelcretfAerutarepmetecafruslioS 82–42,mrofinU oC 25–32,noitairavediW oC

erutsiomecafruslioS tsiomylmrofinU noitairavemertxE

gnihcaeL laminiM egraL

noisoreecafruS laminiM egraL

erutcurtslioS elbatS elbairaV

elcyctneirtuN desolC nepO

elcycrettamcinagrO desolC nepO

tnetnocrettamcinagrO tnatsnoC gnisaerceD

OC 2 esaelerdnanoitcudorp mrofinudnahgiH ralugerridnawoL

5). In addition, nutrient inputs added inagricultural systems can exceed the capacityof the soil to retain nutrients and may result inlarge leaching and/or volatilization losses.

Nutrient gains and losses from anupland field

We consider the within boundary of an uplandfield to be the edges of the farmer s field andthe depth to which the majority of crop rootspenetrate (=1 m) (Figure 2-5). All nutrientscontained within the soil or vegetation of thisfield belong to the landowner. Nutrients areonly added to or removed from the field whenthey cross the field boundary. When a farmer

Plate 2-5

An uncovered upland soil isa harsh environment andlimits the important biologicalprocesses that are related tonutrient cycling in uplandsoils.

48

Figure 2-6

Examples of changes in fieldnitrogen status in a farmer sfield.Within a field: Removing rice grainresults in loss of 30 kg N. Returningrice straw to only part of the fieldresults in an additional loss of 20 kgN to the field where straw was notreturned. The farmer loses 30 kg ofN, and may be inefficiently usinganother 20 kg N.Within a farming system:Removing forage to stall feed cattlewithout returning cow dung results inloss of 30 kg N to the field. Thehousehold does not lose becausethe manure is applied to homegarden, which is part of their uplandfarming system.Between farming systems: Onsloping land, nutrients lost in erosionare deposited in a neighbour s field.The neighbour farmer has gained 20kg N, but farmers A and B each lost5 and 15 kg of N respectively.

Figure 2-5

The farmer s field is an opensystem with much morepotential for losses from cropremoval, animal manure notreturne to the field, erosionand leaching.Compare this to a forest in Figure 2-3. The amount of nutrients movedthrough the system depend on theintensity and quality of management.

sells his products, he also sells nutrients fromhis farm.

Some examples of nutrient transfers areshown in Figure 2-6

2-5 Plant nutrition and nutrientcycles

Essential plant nutrients

Only 16 of the >100 elements that exist in

49

nature are considered essential to most plants(Table 2-8). Of these, carbon, oxygen, andhydrogen make up about 96% of plant drymatter (PDM) and are obtained from the airand water. Nutrient elements vary in theirmobility in the soil and within plants (Table 2-9). Relative mobility describes the comparativemobility of nutrients in plants and helps us to

identify nutrient deficiencies in crops. Similarly,understanding the mobility of nutrients in soilhelps us to understand various aspects offertilizer management (Table 2-10, Part 2-7).

Table 2-8 Functions of essential plant nutrients (other than C, H and O) and their mobility inplants and soils.

laitnessEtneirtuntnalp

selordnasnoitcnuftnatropmItnalpehtni

MDP% ytiliboM

tnalP lioS

stneirtunorcaM

)N(negortiN .sisehtnysotohp,noitamrofnietorP 5.1 5 5

)P(surohpsohP,htworgtoor,refsnart/egarotsygrenEesaesid,htgnertswarts,ytirutamporc

.ecnatsiser2.0 5 1

)K(muissatoP

,ecnanetniamerusserprogruttnalPehtfotropsnartdnanoitalumuccaporc,msilobatemtnalpfostcudorp

.ecnatsiseresaesid

0.1 5 4–3

)gM(muisengaM .sisehtnysotohP 2.0 5 2

)S(rufluStahtsdnuopmocnI.snoitcnufynaM

.noinonirodoedivorp1.0 2 5

)aC(muiclaC-Nybderiuqer,sllawdnahtworglleC

tunroftundnuorgybdnaairetcabgnixif.tnempoleved

5.0 1 2

stneirtunorciM

)lC(edirolhC,ytirutamporcylrae,sisehtnysotohP

.lortnocesaesid10.0 5 5

)eF(norI .noitaripserdnasisehtnysotohP 10.0 2 2

)nM(esenagnaM .noitcnufemyzne,sisehtnysotohP 500.0 – 2

)B(noroB .sllecwenfohtworg/tnempoleveD 200.0 1 3

)nZ(cniZ .ytivitcacitamyznE 200.0 2 2

)uC(reppoCnietorp,noitamrofdeesdnallyhporolhC

.sisehtnys5000.0 2 2

)oM(munedbyloM .snoitcaeremyzne,noitaxif-NemugeL 10000.0 2 2

.nmulocanihtiwytilibomerapmoC.elibomyrev=5,ytilibomroop=1;rettamyrdtnalp=MDP

50

Nutrient availability to plants

Not all nutrients contained in the soil areimmediately available for uptake by plants(Table 2-10). Nutrients are generally dividedinto three groups of availability:

� Available to plants.

� Slowly available to plants.

� Unavailable to plants.

Soil microbiological activity may makenutrients either more or less available. Forexample, when residues with a very wide C/Nratio (e.g., rice straw, woody hedgerow

prunings) are added to the soil, N from thesoil may be temporarily used by the soilmicrobial biomass to fuel the decompositionprocess.

Ideally, just enough nutrients should be madeavailable when the plant needs them (i.e.,nutrient supply and demand aresynchronized). Unfortunately, when nutrientsare readily available to plants they are alsomost likely to be lost from the field (for example,through leaching). By using a suitablecombination of nutrient sources (for example,mineral fertilizers and organic manures),nutrients can be made available over a longer

Table 2-9 The mobility of nutrients in plants and soil can be used to understand nutrientdeficiency systems in plants, and fertilizer management in soils.

elibomsseL elibomeroM

tnalP

noraeppatsrifsmotpmysycneicifeD.)B,uC,eF,nZ,aC,S(sevaelregnuoy

ssel,detimilsiekatputneirtunnehWmorfdevomtonerastneirtunelibom

nihtworgwentroppusotsevaelredlo.sevaelregnuoy

noraeppatsrifsmotpmysycneicifeD.)gM,P,K,N(sevaelredlo

erom,detimilsiekatputneirtunnehWmorfdevomerastneirtunelibomnihtworgtroppusotsevaelredlo

.sevaelregnuoy

lioS

otylekileromerastneirtunelibomsseLdeilppaerewyehterehwotraenniameryllacisyhperaselcitrapliosehtfitpecxe(dniwybyawadeirracroegallitybdexim

.)retawro

eromerastneirtunelibomeroMdnagnihcaeloteudtsolylisae

.noitazilitalovsessolecuderotnekatebtsumeraC

.stneirtunesehtfo

Table 2-10 There are three main categories of nutrient availability, because not all of thenutrients in an upland field can be immediately used by plants.

ytilibaliavAelbaliavanehW

stnalpotselpmaxE

ylidaeRotelbaliava

.stnalp

royletaidemmItnerrucehtgnirud

.porclaunna

,.g.e(srezilitrefelbulosnideniatnocstneirtuNnodlehstneirtun,MOSdezilarenimylidaer,)lCK

.noitulosliosehtnidna,selcitrapliosfosegdeeht

ylwolSotelbaliava

.stnalp

tnerrucehtgniruDroporclaunna

weftxenehtnihtiw.sporc

tnalpsahcus,mrofcinagronideniatnocstneirtuNerehwylralucitrap(serunamcinagrodnaseudiser

larenimelbulosylwols,)ediwsioitarN/CehtMOSehtdna,)etahpsohpkcor,.g.e(srezilitref

.noitazilarenimottnatsisersitahtnoitcarf

elbaliavatoN.stnalpot

gnirudtonylbaborP.emitefils'remraf

liosnodebrosdaro,skcornideniatnocstneirtuN.selcitrap

51

period of time, while reducing the potential forcostly losses.

Nutrient availability is controlled by both thetype of nutrient and the form in which it iscontained. Important management factors foreach nutrient are listed in Table 2-11 and 2-12.

Table 2-11 Important factors for managing N, P and S in an upland system.

tneirtuN srotcaftnemeganamtnatropmI

negortiN

.)8-2traP(sessolgnihcaelecudeRNlacigoloibesaercnI 2 .)9-2traP()FNB(noitaxif

.)9-2,3-2traP(MOSehtesaercnironiatniaM.)8-2traP(yltneiciffesrezilitrefNesU

.)8-2traP(dleifehtotseudiserporcnruteR)8-2traP(seudiserporcnrubtonoD

surohpsohP

.)7-2traP(rezilitrefsaliosotPddA.)9-2,3-2traP(MOSniatniaM

ylidaerhtiwrehtegotsrezilitrefPgniylppaybycneiciffeesu-PesaercnI.serunamlaminadnaseudisercinagroelbasopmoced

rufluS.)8-2traP(seudiserporcnruteR

.)9-2,3-2traP(MOSniatniaM.)8-2traP(seudiserporcnrubtonoD

Table 2-12 Important factors for managing K, Ca and Mg in an upland system.

tneirtuN )8-2traP(srotcaftnemeganamtnatropmI

muissatoP

.sessolgnihcaelecudeRreddofhtiwdefkcotsevilmorferunamlaminadnaseudiserporcnruteR

.dleifehtmorfnekat.yltneiciffeeromrezilitrefKesU

muiclaCreddofhtiwdefkcotsevilmorferunamlaminadnaseudiserporcnruteR

.dleifehtmorfnekat.liosehtotemilrosrezilitrefaCddA

muisengaMreddofhtiwdefkcotsevilmorferunamlaminadnaseudiserporcnruteR

.dleifehtmorfnekat.liosehtotetimolodrorezilitrefgMddA

52

2-6 Nutrient requirements ofintegrated upland systems

Food crops

Four factors that determine the nutrientrequirements of a crop are as follows:

1 Soil fertility status

In very fertile soils, plants may take up morenutrients than are needed to increase yield.Extra nutrient uptake that does not increasecrop yield is called luxury consumption ,and sometimes occurs for K.

2 Crop variety

Improved or modern varieties tend to havea larger concentration of each nutrient intheir tissue, have higher yield potential, andthe ratio of grain (or harvested portion) tototal biomass (such as leaves) is greater(this is referred to as the harvest index(Table 2-13). For these reasons, nutrientofftake in modern crop varieties is usuallygreater than for traditional varieties.

3 Total yield of the crop

Crops need more nutrients to producelarger yields. This also means that morenutrients will be removed in the harvestedportion and more nutrients will be recycledthrough crop residues as yields increase(Plate 2-6).

4 Purpose of the crop

Nutrient requirements depend on whetherthe crop is grown for its tubers, legume orcereal grain, leaves, or fruit (Plate 2-10).Different plant parts have different nutrientcontents. For example, cassava root with4.5 times greater total yield than maize,may contain only half the amount of Ncontained in maize grain (Table 2-14).

Nutrient uptake and removal data for the mainfood crops grown on acid, upland soils areprovided in Table 3-11.

Tree crops

Tree crop nutrient requirements are based onthe same principles that apply to food crops.However, a major difference is that like therainforest, tree crops store nutrients in biomassfor a much longer period as the above- andbelow-ground parts continue to grow. Thenutrients contained in the biomass are not lostfrom the field unless the biomass is laterharvested and removed or burned (e.g., treecrops grown for pulp such as Acacia mangium;rubber trees sold for pulp wood).

We will now look at the nutrient requirementsof crops grown for their sap, fruit, and biomass.

Rubber

A large part of the total nutrient uptake iscontained in the tree trunk biomass, and onlysmall amounts of mineral nutrients areremoved in the harvested product (Table 2-15). This is because the total amount of latexremoved is small (< 1.5 t dry rubber yr-1) andthe latex mainly consists of organiccompounds composed of C, H, O and N.

Most of the nutrients taken up are immobilizedin the rubber tree during the first 5 years ofgrowth. This is why fertilizer nutrients must beapplied during the immature period so that thetree grows rapidly and reaches a tappable sizein 5-6 years. After 5-6 years a large amount ofnutrients is recycled through leaf fall, and aftersix years nutrient removal in latex begins. Ifrubber trees are properly fertilized during theimmature growth phase, only small amountsof N, P and K are required to sustain productionand replenish nutrients removed in latex duringthe mature crop growth phase.

Oil Palm

In comparison to rubber, oil palm has a largeannual requirement for nutrients. About 30%of the N, P, and K taken up by the crop isremoved in the harvested fruit bunches (Table2-15). On most acid upland soils, largeamounts of fertilizer nutrients are required toproduce and sustain economic yields. The oilpalm has a particularly large demand for K.However, the requirement for fertilizer nutrient

53

Photo 2-6

Over 100 kg of K is requiredto replace the amountremoved in oil palm bunches,whereas only 13 kg of K isrequired to replace theamount removed as rubberlatex per year.

Table 2-13 Example of how improved varieties have greater nutrient uptake than localvarieties.

porC

dleiY niarG wartS

aht 1- ahgk 1-

niarG wartS N P K N P K

yteiravecirdevorpmI 4 4 84 01 42 42 6 061

yteiravecirlacoL 1 2 81 4 5 21 1 05

Table 2-14 The total yield for cassava roots may be 4—5 times greater than for maize, butcontain only half the amount of N. Nutrient uptake in a crop partly depends on whether it isgrown for grain, tubers, fruit, or biomass.

porC tcudorP dleiYtrapdetekraM

morfdevomerdleif

dnuorg-evobAgniniamernoitrop

dleifno

aht 1- ahgk 1- ry 1-

N P K N P K

avassaC srebuthserF 81 23 31 05 46 61 24

eziaM )laerec(niarG 4 36 21 03 73 6 83

naebyoS )emugel(niarG 1 66 21 02 31 2 61

ssarG ssamoiB 4 09 32 021 – – –

ananaB tiurF 52 34 11 051 59 02 054

54

traptnalPN P K

ahgk 1-

)pas(rebbuR

ahseert005–004(sraey03retfassamoiblatotnI 1- .) 0051 005 0051

ryrebburyrdt1nidevomeR 1- . 21 4 31

)sehcnubtiurf(mlapliO

ahsmlap841(ssamoibniekatpulaunnA 1- .) 191 26 813

ahsehcnubtiurft42(noitcudorphcnublaunnanidevomeR 1- .) 37 72 111

)tiurf(eeffoC

ahseert005,1.seertdloraey-5rofekatpuporclaunnA 1- dleiY.ahgk001,1 1- .naebneerg

58 81 28

aht1nidevomeR 1- .tiurfelohwsasnaebneerg 43 6 94

ahseert333,1(htworgfosraey5retfasmetsnidevomeR 1- .) 53 9 71

muignamaicacA )ssamoib(

.htworgfosraey8retfaeertybpunekatlatoT 58 81 28

.knurtnidevomerstneirtunlatoT 43 6 94

Table 2-15 Comparison of the amount of nutrients taken up and/or removed from a field bycorps grown for sap, fruit, or biomass products.

inputs can be reduced by applying empty fruitbunches (factory residue) or bunch ash(burned empty fruit bunches) in the field.

Coffee

The amount of nutrients removed from the fieldis reduced if the pulp is returned to the fieldand only green beans or parchment coffee areremoved. Of course, nutrient removal isgreater if pruned stems are used for firewood.

Acacia mangium

Acacia mangium is a tree grown for wood orpulp (Table 2-15). A. mangium is reported tofix about 50% of its N requirement (Table 3-25).

Nutrient uptake and removal information forthe main tree crops grown on acid, upland soilsare provided in Table 3-11.

Livestock

Ruminants are often the most importantlivestock component of acid, upland farmingsystems. Feed supplements are not usedmuch by upland farmers. Forages and cropresidues are and will continue to be the majorsource of energy, protein, and mineral nutrientsfor ruminants. Therefore, understanding therelationship between the nutrient status of acid,upland soils and ruminant nutrition isimportant.

The major effect of livestock on soil fertility isthrough the provision of animal manure andits effect on chemical, physical, and biological

55

soil properties. A potential indirect effect isthat nutrient losses from erosion and surfacerunoff will be reduced where forage strips havebeen planted along contours to provide animalfeed.

Over-grazing of livestock, however, may resultin soil compaction, which reduces waterinfiltration and increases surface water runoff.

Major nutrients required by livestock

The macronutrients required by ruminants arethe same as those required by plants (Table2-8), except that animals also require chlorine(Cl) as a macronutrient, whereas it is amicronutrient for crops. Chlorine is usuallysupplied as common table salt (NaCl).Livestock also require iodine (I) and selenium(Se), and some other micronutrients notconsidered essential to plants.

In farming systems on acid, upland soils, poorsoil fertility is one of the main factors limitingmineral uptake by ruminants. Since animalsderive most of their forage from upland fieldspoor in nutrients, the livestock are often alsoaffected by mineral deficiencies. If there is noP in the forage eaten by livestock, there is noP for the animal (Plate 2-7)!

Livestock nutrient uptake

Livestock nutrient uptake is the product of thenutrient concentration in the forage, the totalamount of forage consumed, and theavailability of the nutrients in the forageconsumed (digestibility).

The concentration of nutrients in plantsdepends on:

� Soil nutrient status (most acid, uplandsoils are deficient in minerals needed bylivestock).

� Plant species (some plants have agreater nutrient contents than others).

� Stage of maturity (forage digestibility, andhence nutrient availability, decreases withincreasing age of the forage).

The total amount of forage consumed dependson the age of the forage and the size of animal.Larger animals will consume more forage thansmaller ones. As a forage ages, animals willeat less of it.

Major mineral deficiencies in livestock inIndonesia

Major mineral deficiencies in livestock inIndonesia include P and N (i.e., crude protein)because most acid, upland soils contain verylittle plant available P and farmers do notprovide sufficient amounts of N-rich forage(i.e., legume species) to their livestock.

Symptoms of poor nutrition

Signs of mineral deficiency include loss of bodyweight, loss of hair, de-pigmented hair, skindisorders, noninfectious abortion, diarrhoea,anaemia, loss of appetite, grass tetany (dueto low blood Mg content), low reproductivefertility, bone abnormalities and depravedappetite (they eat the stall!).

Remedial measures

The recommended remedial measures are asfollows:

seicepSekatnirettamyrD

deriuqererunaMdecudorp

daehgk 1- ry 1-

)gk053(gnikrowetaredom–elttaC 007,2 000,11

)gk04(ytivitcamuidem–taoG 044 A/N

)gk004(gnikrowetaredom–olaffubretaW 003,3 A/N

Table 2-16 Dry matter intake and manure production for cattle, goats and chickens.

56

� Improve soil fertility by adding P fertilizerto increase legume and grass biomassproduction in mixed grass legumepastures.

� Incorporate more legume species in thefarming system to supplement ruminantcrude protein (N) supply.

2-7 Integrated nutrientmanagement: making practicaldecisions

Integrated nutrient management is the efficientuse all types and forms of nutrients, both thoseoriginating from the field or farm as well asthose from outside the field or farm. Theobjective is to manage a productive,sustainable, and stable system, at the smallestcost to the farmer. Many practices can formpart of an integrated nutrient managementstrategy. What may seem as a reasonablepractice to recommend on paper, however,may not be realistic to carry out in practice.Four aspects that are usually considered by ahousehold in deciding on soil fertilitymanagement practices include the technicalfeasibility, economic returns, practicalfeasibility, and social acceptability (Table 2-17).The extension worker should try to understandthese considerations when working with farmhouseholds.

Different approaches to soil fertility andcrop management

The soil and vegetation in a field are a nutrientbank and should be protected against losses(Figure 2-5). The farmer should harvest aneconomic benefit for each kg of nutrientremoved from the field. For example, thefarmer does not benefit from nutrients lost toerosion whereas a crop that takes up nutrientsand is sold by the farmer earns income. Eachkilo of nutrients conserved reduces thefarmer s costs for purchased mineral fertilizernutrients.

There are three main approaches to soil fertilitymanagement on acid, upland soils:

1 Plant crops adapted to indigenous soilnutrient supply.

2 Improve the soil fertility to meet thecrop s requirements (this includes cropsnot well-adapted to acid, upland soils likesoybean).

3 Select improved, adapted crop varietiesand improve soil conditions according tocrop requirements.

We will now consider these three approachesin turn.

1 Plant crops adapted to the indigenoussoil nutrient supply.

This is often considered the low externalinput approach. It is argued that it may be

Photo 2-7

Livestock feeding mainly ongrasses grown on low fertiltysoils will likely suffer frompoor nutrition. The grass hasa low P content, thus theanimals eating the grass willalso suffer from low P. Thisis why P is a major nutrientdeficiency for both plants andanimals in upland systems.

57

more feasible for the farmer to change thecrop being grown, than to apply largeamounts of nutrients.

In this approach minimal nutrient inputs areprovided and only crop plants able to growunder the indigenous soil nutrient supplyare planted. Cassava extracts nutrientsvery efficiently from degraded soils and istherefore often wrongly blamed for soilnutrient depletion. In fact, cassava may bethe only crop that will grow on acid, low Pstatus soils. However, after severalseasons without fertilization, the soil Ksupply is depleted and yields are limitedby low soil K status.

Planting crops adapted to indigenous soilfertility is viable only in the short term. Inthe long run, such practices lead to soilimpoverishment and a progressivereduction in the range of crops that can becultivated at a particular site. In addition,as productivity decreases, the soil becomes

more susceptible to erosion and a chainreaction of soil and environmentaldegradation begins (Figure A-1).

2 Improve soil fertility to meet the crop srequirements.

In this example, crops with the greatestmarket potential are selected and soilproperties are modified so that the crop cangrow well. For example, for soybean togrow well in acid, upland soils, Al toxicitymust be decreased and soil P statusimproved. Under proper management, soilfertility is gradually increased and thefarmer is able to cultivate a wider range ofcrop species. Crop establishment is rapid,resulting in a reduction in soil losses fromerosion. This approach usually requireslarger amounts of inputs.

3 Select improved but adapted cropvarieties and improve soil conditionsaccording to crop requirements.

tcepsA elpmaxE odottahW

lacinhceTytilibacilppa

ruotnocanoseertwefagnitnalplliW?noisoreliosesaercedworegdeh

ybtemebsdeentneirtunehtllanaC?erunamlaminaylnognisu

sihtniderevoctonseigetartsroFmorfstluserredisnoc,koobdnah

)4petS,1traP(slairtdleifelpmis.secneirepxe'sremrafrehtodna

cimonocEsnruter

detnalperunamneergahguohtlAedivorpyamwollafmret-trohsagnirud

ahNgk05 1- Nlacigoloiboteud 2

05esahcrupotyltsocsseltisi,noitaxif?Nrezilitreffogk

eulavhgihatnalpyamremrafehTdna,erunamneergehtfodaetsniporc

.Nrezilitrefehtyub

tegdublaitrapatuoyrraC.)4petS,1traP(sisylana

lacitcarPytilibisaef

aht01yrracottnawremrafehtseoD 1-

?dleifehtoterunamtneiciffusgnidivorpkcotsevilehterA

?sdleifehtroferunam

.remrafehthtiwssucsiD

yllaicoSytilibatpecca

nworgebotseertwollaegallivehtlliW?sdleifniatrecno

evitagenaevahecitcarpehtlliW?tcapmilatnemnorivne

.remrafehthtiwssucsiD

Table 2-17 Aspects to considered when choosing nutrient management strategies.

58

Plate 2-8

a) Almost all C, N, and S islost when organic materialsare burned. These nutrientsmust be replaced withmineral fertilizers. Smokehaze also damages health!

b) Animal manure onlyadds nutrients to the feld ifanimals that produced itwere fed on forage grown ona different field.

c) Incorporate fertilizer inthe soil to reduce nutrientlosses and improve nutrientavailability to crop plants.

d) Grow improved varietiesthat are adapted to acidsoils. They usually requirelarger nutrient inputs thanlocal varieties like this clonalrubber planted with legumecover plants.

e) When P deficiency hasbeen corrected, a fullresponse to N and Kfertilizers is obtained. In theforeground, crops receive noP fertilizer and the responseto N and K fertilizer is verypoor. In the background,where low soil P fertilitystatus has been corrected, alarge response to N and Kfertilizers is obtained.

f) Large soybean yieldscan be achieved on acidsoils by using sufficientinputs of lime and fertilizers.

g) Cassava is often grownon poor soils as a cash crop,particularly when starchprices are high. Nutrientsremoved in crop productsmust be replaced to avoidsoil mining .

a b

c d

e

f g

59

An intermediate approach is to selectadapted crop species and crop varietiesand provide some nutrient inputs. Forexample, local rubber can be replaced withimproved clonal rubber. Rubber is adaptedto acid upland soils, but some nutrientinputs are still required to exploit the greateryield potential of the more nutrient-demanding clonal rubber.

Soil fertility recapitalization

Because of the effects of nutrient mining,erosion and other improper land managementpractices, acid upland soils usually requirerehabilitation before sustainable andeconomically rewarding agriculture can bepractised. During the rehabilitation process,soil nutrient stocks must be replenished byadding mineral fertilizers and by increasing the

amount of crop residues and other organicmaterials returned to the soil. Nutrient stocksmay be enriched with a range of differentnutrient sources (Table 3-12, 3-14). Usuallymineral fertilizers are required because of thecost, and difficulty of handling large amountsof bought-in organic manures and cropresidues. In any case, organic manures andcrop residues are usually not available locallyin sufficient quantity.

Nutrient deficiencies should be eliminatedstarting with the most limiting nutrient (Part 2-8). The major soil nutrient problems in acid,upland soils are low N, P and K status, and Al-toxicity. K and Mg are particularly deficientunder the following conditions:

� soils that have been cropped for severalseasons,

Table 2-18 Sources of nutrient for soil rehabilitation

ecruoS egatnavdA egatnavdasiD

dnarezilitreflareniM.)8-2traP(emil

.ylppadnatropsnartotysaE.tceffedipaR

elbaliavaebtonyaM.yltsoC.saeraetomerniyllacol

,erunamlaminAporcdnatsopmoc

morfdeniatboseudiser-2traP(secruosmraf-ffo

.)8

cinagro,stneirtunotnoitiddanIroflairetamedivorpserunam

rettamcinagrolios.tnemhsinelper

yllacolelbaliavaebtonyaMyaM.ytitnauqtneiciffusniro

ottluciffiD.yltsocyreveb.tropsnartdnaeldnah

NlacigoloiB 2 noitaxif.)9-2traP()FNB(

dnadexifsiNcirehpsomtA.mrafehtotnithguorb

ebyamrezilitrefKdnaPnoFNBesaercniotderiuqer

.sliosdnalpu,dica

llafniaR tsocontadeddastneirtuN .stnuomatneiciffusnI

nideniatnocstneirtuNdnaffonurecafrus

otnideirracliosdedore.mrafeht

tsocontadeddastneirtuN

emocebsahmrafsrobhgieNdecudernignitluserdedore

gnimrafehtniytilibats.ytinummoc

ybpunekatstneirtuNrosporcgnitoorpeed

tadetisopeddnastnalpfaelniecafrusliosehtseudiserporcdnarettil

ontadeddaebyamstneirtuNtsoc

tnalpelbatiusdnifottluciffiDaecudorptahtseicepsdnatcudorpelbatekram

lAfotnareloterastoorerehwfotnuomaehT.yticixot

siliosbusehtnistneirtun.llamsyrev

60

� crop residues have been removed, and

� little or no fertilizer K and Mg has beenapplied.

Nutrients are only added to the field s nutrientbank (the soil and vegetation) by bringingnutrients in from sources outside the field orfarm (Part 2-4). It is very important to identifywhere there is a need to import additionalexternal nutrient inputs. Even where organicnutrient sources are available at economicprices, there may not be sufficient materialavailable in a particular locality. For thesereasons it is usually necessary to importnutrients in the form of mineral fertilizers.

Less fertilizer is usually required to eliminateN, K, or Mg deficiencies than to overcome Pdeficiency or Al-toxicity. Nutrient deficienciesmay be eliminated by applying fertilizer nutrientinputs using either an all-at-once , or a step-by-step approach (Figure 2-7).

1 All-at-once approach to build up soilnutrients

With this approach, the major limitingnutrient or toxicity problem is immediatelyovercome by a large one-time fertilizerapplication (Plate 2-8). This approach canbe used for all nutrients, but is particularlysuitable for overcoming P deficiency, lowpH and Al toxicity. This is because P is notlost due to leaching (except in very sandysoils) and is retained in the soil on fine soilparticle surfaces (e.g., clay).

The approach is particularly suited wherea large amount of P must be applied beforea crop response is detected (Figure 2-7).After the blanket application (e.g., 1-1.5 trock phosphate ha-1, 300-600 kg P2O5 ha-

1) has been applied, smaller maintenancedoses are applied to prevent soil nutrientdepletion.

2 Step-by-step approach to build up soilnutrients

The incremental approach can be used ifthe farmer cannot afford to purchase all ofthe required fertilizer at once and where aresponse to small amounts of fertilizer is

expected. However, this approach is onlyrecommended for nutrients that canaccumulate in the soil such as P, Ca, andto some extent K and Mg, and for materialsthat have a long-term residual effect (Pfertilizers and lime).

Two approaches for increasing soil nutrientstatus in a field are now described.

1 Only fertilize part of the field each timewith the recommended dose

For example, instead of applying 1 t ha-1

rock phosphate to the entire 1 ha field, thefarmer applies 500 kg of rock phosphateto 0.5 ha each year. After two years, theentire field has been fertilized.

A variation of the above approach, is toplace the fertilizer near the crop. Forexample, if maize is planted in rows 60 cmapart, rock phosphate could be applied toa 20 cm band, along the planting strip(equivalent to 30% of the field). However,this technique is more labor intensive andrequires careful planting so thatsubsequent crops are planted into thefertilized soil.

2 Apply a smaller dose to the entire field

For example, 250 kg of rock phosphatecould be applied to the entire 1 ha field, sothat after four applications the entire field

Figure 2-7 Response to P fertilizer and twocontrasting approaches to P recapitalization.

61

has been fertilized with the equivalent of aone-time blanket application of 1 t ha-1 rockphosphate.

With the first approach, at least a portion ofthe field receives the required dose of fertilizerto overcome nutrient deficiencies. If applyingfertilizer at the recommended rate producesgood results the farmer will be more likely toapply the full amount to another portion of thefarm in the following season, or even purchaseenough material to fertilize the entire field.

With the second approach the amount offertilizer applied may not be sufficient toproduce a visible improvement in crop growth(blue line in Figure 2-7). One way to determinethe response is to test the application rate in asmall plot as described in Step 4 in Part 1. Ifthe amount of fertilizer applied does not resultin a satisfactory yield increases, the farmermay not want to apply fertilizer again!

Whichever approach is used, soil fertilityimprovement should be combined with soilerosion measures (e.g., contour strips) and theintroduction of crop species and varieties thatcan exploit the more fertile soil.

Balanced fertilization

Balanced fertilization is achieved when thecropping system is supplied with the correctproportions of N, P, K, Mg and other nutrients.N and K fertilizer supplied in excess of thecrop s requirements may be lost due toleaching and, for N, volatilization. Excessnutrient supply can increase the amount ofnutrients taken up in the grain and strawwithout increasing yield. In such situations ofexcess uptake, or luxury consumption , theamount of nutrients removed from the field islarge, particularly when the straw is notretained in the field. Excessive application

Table 2-19 Some potential negative effects of unbalanced fertilization.

rotcaF stceffeevitagenlaitnetoP

NevissecxE )tsalbecir,.g.e(esaesidotytilibitpecsussesaercnI

KtneiciffusnI )ecirnitopsnworb,.g.e(esaesidfoytilibissopsesaercnI

emilnideddaaCevissecxE noitartnecnocaCevissecxeybdecudniycneicifedgM

N limited crop growth K limited crop growth

N P K Plant N P K PlantFigure 2-8 N and K limited crop growth, according to Liebig s Law of the Minimum.

62

rates may also lead to negative effects suchas increased soil salt content andenvironmental pollution.

When fertilizer nutrients are applied in thecorrect proportions, fertilizer use is said to bebalanced. Unbalanced fertilization can resultin a waste of fertilizer and can also have somenegative effects on plant growth (Table 2-19).Balanced fertilizer use also reduces fertilizercosts.

In Figure 2-8 each column represents adifferent nutrient. At first, crop yield is limitedby the supply of N, and K and P are suppliedin excess of requirements (N-limited cropgrowth). After the supply of N has beenincreased, crop yield is increased but limitedby the supply of K while the availability of Pand N exceeds requirements.

Most farmers tend to add N and P fertilizers,and neglect to apply K fertilizer. Under such

tneirtuNnoitartnecnoc

tneirtuNytilibaliava

ecruostneirtuN

detartnecnoC elbaliavaylidaeR elacs-egralgniriuqersrezilitreflareniM,aeru,.g.e(tnempiuqednatnalpgnissecorp

HN 4 ON 3 HN, 4 OS 4 OSgM,63-PS,PST,lCK, 4.

gnissecorplaminimgniriuqersrezilitreflareniM.etahpsohpkcor,etimolod,eticlac,.g.e(

detartnecnocsseL elbaliavaylwolS,seudiserporc,.g.e(secruostneirtuncinagrO

.)onaugtab,serunamlamina,sdeew

Table 2-20 Main categories of nutrient-containing materials.

secruostneirtuncinagrO rezilitreflareniM

eromnoitisopmoctneirtuN.decnalab

nehwdecnalabylnosinoitisopmoctneirtuNlarevesnehwrodesuerasrezilitrefdnuopmoc

.denibmocerasrezilitreftneirtun-elgnis

.lioshtiwylwolseromtcaeR .lioshtiwyldipartcaeR

tneirtundnaretawliosesaercnIrofleufedivorp,yticapacgnidlohdnaarolfliosfonoitacilpitlumeht

otsdicacinagroedivorp,anuaf.stneirtunliosevlossid

ylppusehtdnaelbaliavaylidaereromerastneirtuNycneuqerfdnaetarehtybdetalugerylisaeebnac

.noitacilppafo

,stneirtunfoegnarregralaniatnoC.stnemeleecartgnidulcni

erastneirtuN.stneirtunfoegnarrellamsaniatnoCotyltsocssel(mrofdetartnecnocanideniatnoc

.)erotsdnatropsnart

cinagrofotnetnoctneirtuntcaxE.nwonktonyllaususiserunam

.nwonksirezilitreflarenimfonoitisopmocehT.seitirupmifoeerfsirezilitreflarenimytilauQ

dnatnetnoctneirtunrewoLehtfoeromseriuqererofereht

.tneirtunfogk1ylppusotlairetam

ylppusstnuomallamS.tnetnoctneirtunregraLluferaC.tneirtunfostnuomaegralylevitarapmocsessoltneirtunecuderotderiuqersitnemeganam

reporpmI.noitazilitalovdnagnihcaeloteud.stnalpllikroerujninacnoitacilppa

Table 2-21 Characteristics of mineral fertilizers and organic nutrient sources.

63

unbalanced fertilizer use, yields decrease andfarmers usually respond by increasing theamount of N or P fertilizer applied. Yields,however, are not increased until K has beenadded.

How to determine the most limitingnutrient?

The best way to determine which are the mostlimiting nutrient(s) is by plant and soil testing.Many farmers do not have access to plant andsoil analysis, however, and the extensionworker has to rely on other methods. Variousproxy methods and tools can help theextension worker and farmer diagnose thenutrients that may be limiting crop growth.Simple farmer test plots can also be used totest out different recommendations.

2-7 Nutrient Sources

General

Plants take up nutrients both directly from thesoil and from nutrients applied to the soil inthe form of organic nutrient sources (e.g., cropresidues and animal manures) and mineralfertilizers. Mineral fertilizers are either minedor manufactured to provide plant nutrients inconcentrated forms that meet a crop s nutrientneeds. Products range from standard singlenutrient fertilizers (e.g., urea, TSP, KCl) tocompound fertilizers (e.g., 15-15-6, 12-12-17+4) and slow release fertilizers (e.g., ureabriquettes). All mineral fertilizers originate fromnatural sources (urea from atmospheric N2, Pfrom rock phosphate, K from undergroundpotash deposits).

Nutrient availability for plants may depend onreactions between the fertilizer material andthe soil. For example:

� Soil pH is increased rapidly after anapplication of calcite but only in thepresence of sufficient soil moisture.

� The soil must be sufficiently acid (pH<5.5) to react with rock phosphate andrelease P for plant uptake.

Nutrient availability may also be affected bythe composition of animal manures and cropresidues. For example:

� Animals fed with a nutrient-poor dietproduce nutrient-poor manure.

� Organic residues with a narrow C/N ratioare a readily-available source of N (e.g.,legume crop residues) while those with awide C/N ratio are only slowly available(e.g., rice straw).

Three major categories of nutrient sources areshown in Table 2-20. The properties of organicand mineral fertilizer nutrients are comparedin Table 2-21.

Effect of nutrient imbalances

Mineral fertilizers are concentrated nutrientsources and when incorrectly used inunbalanced proportions, losses may occur andcrop response is reduced. For example:

� Losses may be large when one nutrientis supplied in a readily-available form, inlarge quantities and in excess of thecrop s requirement.

� A single nutrient is applied, but responseis poor due to deficiency of anothernutrient.

Micronutrient deficiencies usually only appearafter many cropping seasons, but the soil sreserves of micronutrients are more rapidlydepleted if only macronutrient nutrient sourcesthat do not contain micronutrients are applied.

Animal manures and vegetative biomasscontain some micronutrients (depending onwhat the animal has been fed), whereas themost commonly used mineral fertilizers suchas urea, TSP, ammonium sulphate, and KCldo not contain micronutrients.

Effect of organic manures and mineralfertilizer on soil properties

Organic manures and crop residues are animportant source of soil organic matterreplenishment and therefore contribute to themaintenance of soil structure.

64

tneirtuNssoL

yawhtapsessolnignitlusersnoitidnoC sessolgnicuderrofseigetartS

N)aerU(

noitazilitaloV

.sliosydnasotnoitacilppA .liosehthtiwaeruximsyawlA

.ecafrusliosnotfelrezilitreF .spirtsworranroselohelbbidniylppA

.sdoirepyrd,tohninoitacilppA.rezilitrefgnitsacdaorbretfa,etagirriylthgilroeoH

.snoitacilppatilpsnirezilitrefylppA

.noitategevgninruB !noitategevnrubtonoD

gnihcaeL

.sliosydnasotnoitacilppA .serunamlaminadnaslairetamcinagroddA

hgihnistnuomaegralfonoitacilppA.saerallafniar

snoitacilppatilpsforebmunehtesaercniroylppatilpS.deriuqereraNfosetarnoitacilppaegralerehw

decnalabnumorfycneiciffeesuNrooP.noitacilpparezilitref

ehtybderiuqerstneirtunllafonoitacilppaehtecnalaB.)7-2traP(porc

noitacifirtineD

dnarepeedotetartinfotnemevoM.liosehtnihtiwstekcopdetcapmoc

.noitarealiosdnaeganiardevorpmI

.sliossutatsrettamcinagrohgiH .)etaflusmuinomma,.g.e(secruosetartin-nonesU

.sliosdeggolretaW sniardllatsnI

noisore/ffonuR

sdnalgnipolSdnadellortnocedivorp,liosotnirezilitrefetaroprocnI

.serusaemnoitavresnocliosllatsnidnanoitagirrithgil

sdleifdelevel-ylrooP dnalehtleveL

erutsiomliosetauqedanIerofebhguolp(serusaemnoitavresnocerutsiomtpodA

.)hclumylppa,sdnubllatsni,sniar

Table 2-22 Strategies to reduce losses when nutrients are applied to soil as mineral fertilizers.

65Table 2-22 ....continued

tneirtuNssoL

yawhtapsessolnignitlusersnoitidnoC sessolgnicuderrofseigetartS

PPST(

ro)63-PS

gnihcaeL saerallafniarhgihnisliosydnaS serunamlaminadnaseudiserporcylppA

noitaxif-P)1-2traP(

nigirocinaclovtnecerfoslioStcatnocrezilitrefecuder(porchcaeotsdnabniPylppA

)lioshtiw

sliosyalcemosninoitaxif-Paht1(rezilitrefPfoesodlaitiniegralylppA 1- kcor

,noitaxif-Pecuderot5.5Hpotemilylppa,)etahpsohp.noitaxif-Pecuderotgalscisabroetacilismuiclacdda

noisore/ffonuR )aerurofsa( )aerurofsa(

K)lCK(

gnihcaeLhtiwdenibmocllafniarhgihoteudsessoL

ahgk001>(setarnoitacilppaegral 1- .)lCK001<(sesodrellamsdnasnoitacilppatilpsnilCKylppA

ahlCKgk 1- .)

noisore/ffonuR )aerurofsa( )aerurofsa(

S,SA(

,etireseik)muspyg

noitazilitaloV )aerurofsa( )aerurofsa(

gnihcaeL llafniarhgiH )aerurofsa(

noisore/ffonuR )aerurofsa( )aerurofsa(

aC,eticlac()etimolod

gnihcaeL llafniarhgiHeseht(etahpsohPrepuSelgniSroeticlacsaaCylppA

.)muspygnahtdehcaelylisaesselerasmrof

noisore/ffonuR )aerurofsa( )aerurofsa(

gM,etimolod()etireseik

gnihcaeL llafniarhgiHmrofsihtnidehcaeltonsitisaetimolodsagMylppA

etireseiknisahcumsa

noisore/ffonuR )aerurofsa( )aerurofsa(

66

Ammonia-based N fertilizers cause soilacidification. Where ammonium sulphate hasbeen used in large quantities (i.e., >400 kgfertilizer ha-1 yr-1) it may be necessary to correctthe soil pH with an application of agriculturallime.

Some mineral fertilizers, especially lime, havebeen identified as the cause of soil hardening,making cultivation more difficult. The saltcontained in some mineral fertilizers (referredto as the salt index) can adversely affect someimportant soil microbes, but this is usually nota problem with organic nutrient sources.

Mineral Fertilizer

This section discusses the fate of nutrientswhen various materials are added to the soil.Nutrients are either absorbed by the crop,stored in the soil or made unavailable to theplant by various soil processes (Table 2-22).

1 Management for efficient fertilizer use

The goal of proper fertilizer and limemanagement is to make optimal use ofnutrients already in the system, whileminimizing external nutrient inputrequirements to produce the maximumeconomic yield. The amount of externalinputs required depends on the soil supplyand the crop demand. The most importantaspects of fertilizer application are timing,placement, and the amount applied.Strategies to reduce losses are describedin Table 2-22

2 Timing

Fertilizer application should be carried outafter weeding so that weeds do not benefitfrom the fertilizer. N fertilizer should onlybe applied when there is sufficient moistureto allow efficient uptake. Large applicationsof N fertilizer can injure and sometimeseven kill the plant.

Timing of fertilization depends on thecharacteristics of the fertilizer material andthe crop requirements. For example, it isparticularly important to apply N fertilizerat the correct crop growth stage when use

efficiency is greatest. Nutrient-useefficiency is determined partly by the sizeand effectiveness of the crop s root system,crop growth rate, crop nutrientrequirements during the growing season,and the duration of crop growth.

Correct timing is more important forfertilizers with a short residual life and greatmobility in the soil (e.g., N fertilizers) andless important for fertilizers with a longresidual life and poor mobility in the soil(e.g., P fertilizers) (Table 2-23).

3 Placement

The appropriate placement strategydepends on the fertilizer material, crop, andcrop spacing. If possible, all mineralfertilizers should be incorporated in the soil.Fertilizer application methods arecompared in Table 2-24. In particular, Nfertilizers should be incorporated in the soilto reduce volatilization losses. However,urea placed too close to a young seedlingplant may scorch the roots and shoot base.Losses of applied P and K fertilizer due tosurface runoff and erosion of the top soillayer are smaller where fertilizer materialsare incorporated in the soil.

4 Mixing of fertilizers with seed

Some fertilizers may be mixed with seedsbefore planting. For example, calcium andphosphate fertilizers are sometimes mixedwith groundnut seed before planting. Inmost cases, fertilizer should not be applieddirectly to the seed hole. It is often betterto first place the fertilizer in the planting holeand then cover the fertilizer with a 3—5 cmlayer of soil before planting the seeds. Forexample, fertilizers with a high salt contenttend to draw water out of seeds.

5 Mixing of mineral fertilizer with organicmaterials

Mixing N and P fertilizers with crop residuesand/or animal manure provides nutrientsfor micro-organisms and therefore speedsup the rate of decomposition of the organicmaterials. Similarly, the organic acids

67

produced during the decomposition oforganic materials can help dissolve lesssoluble mineral fertilizers (e.g., rockphosphate).

6 Distance from crop

Fertilizers should be placed near the rootzone of crops. For tree crops, this usuallymeans applying fertilizers in a circle withinan area described by the outer edge of thecrop plant s leaves (the so-called dripcircle ). In general, fertilizers should beapplied 5-15 cm from the stem of annualcrops, depending on the crop age.

7 Reduction of N volatilization losses

Organic materials should not be burned asthis results in the loss of C, N and S.Incorporate N-containing fertilizers and

manures in the soil and do not apply N-containing fertilizers to slightly wet soilswhen volatalization losses will be greater.

Animal manure

Organic manures are comparatively easy touse because their nutrient content is generallywell balanced. There are, however, severalways to increase fertilizer use efficiency andeffectiveness.

1 Timing

Timing of applications is less important thanwith mineral fertilizer. Animal manuresshould be applied at crop planting, becauseof their slower rate of nutrient release.

2 Placement

Table 2-23 Loss pathways, relative mobility, residual effect, and recommendations forproper timing and application of mineral fertilizers.

rezilitreFlairetam

ssolniaMyawhtap

*ytiliboMlaudiseR

tceffefognimitdednemmoceR

noitacilppa

aerU,gnihcaeLnoitazilitalov

hgiH1tuobA

porc

egralrofsnoitacilppa-tilpsesUgk05>(rezilitref-Nfosetarnoitacilppa

ah 1- ybsessolecuderot)rezilitrefneewtebynorhcnysehtgnisaercni

,.g.e(ylppustneirtundnadnamedporcelcinapdnagnirellittaecirotNylppa

.)noitaitini

muinommAetaflus

,gnihcaeLnoitazilitalov

hgiH1tuobA

porc)aerurofsa(

63-PS/PST,noisorE

porclavomer

woLlareveS

sraey.gnitnalpotroirpllaylppA

kcoRetahpsohp

,noisorEporc

lavomerwoL

lareveSsraey

.5.5<HpliosfiylnoylppA

.gnitnalpotroirpllaylppA

lCKporC

,lavomergnihcael

otmuideMhgiH

lareveSsporc

ahgk001< 1- otroirpecnoylppa,lCK.gnitnalp

ahgk001> 1- -tilps3–2niylppa,lCKsnoitacilppa

/etimoloDeticlac

,noisorEgnihcael

otwoLmuideM

lareveSsraey

.gnitnalpotroirpllaylppA

liosnistneirtunfoytiliboM*

68d

ohte

mn

oitaro

proc

nIse

gatnav

dA

segat

navdasi

D

tondnatsacdaor

Bdetaroprocni

dipaR.tsoc

robalrella

mS

.noitacilppa

ebya

mstneirtun

rezilitrefrehto,noitazilitalov

ottsoleb

yam

Nbrosba

otelba

ebtonya

mstoo

R.noisorelioshguorhttsol

.sdoirepyrd

gnirudstneirtun

eohro

wolpdnatsacdaor

B.

mc51

–01ot

tsebeht

sisiht,yltcerroc

enodfImorf

sessolecuder

otdohte

m.noisoreliospot

dnaffonurecafrus

elbaliavatneiciffusevahton

yam

ohw

remraf

ehtrof

yltsoC

.sihtod

otruobal

gnieohthgilsdnatsacdaor

Bmc

2ot

emo

S.noitaroprocnietelp

mocsseL

.ffonurdna

noisoremorf

noitcetorp

gnidnaB

ehtot

esolcdecalp

erastneirtu

N.

metsystoors'tnalp

porc.evisnetni

ruobaLelbbi

Deht

otesolc

deilppaera

stneirtuN

.stoors'tnalp

porc

Tabl

e 2-

24

Adv

anta

ges

and

disa

dvan

tage

s of

diff

eren

t met

hods

of m

iner

al fe

rtili

zer

appl

icat

ion.

Mulching has several benefits for the topsoilenvironment. Mulched material usuallydecomposes and releases nutrients sloweras compared with residue incorporated intothe soil. The delay in nutrient release canbe desirable under situations wherenutrients are not severely limiting to plantgrowth. A drawback of mulching, however,is that the potential for N losses due tovolatilization is greater than where thematerial is incorporated in the soil.

To speed up residue decomposition andnutrient release, some organic by-products(e.g., oil palm empty bunches) should bemixed with soil and incorporated in thebottom of tree crop planting holes.

3 Applying manure to crops

Only about 25% of the organic material,40% of N, 50% of P, and 45% of K ingestedby animals is returned to the soil, becausenutrients are removed in animal bodytissues and losses occur during urineevents and manure handling. About 30—50% of N, 20% P, and 50% K in appliedmanure may be taken up by the first cropafter application.

For farm yard manure (FYM) (comprisingfaeces, urine, crop residues and soil mixedwith straw) applied to the soil, about 30%of N, 60-70% of P and 75% of K will beavailable to the crop.

Nutrients contained in urine are morereadily available to plants because they arealready in solution. Because of its large Ncontent, urine stimulates soil microbialactivity and increases the rate of cropresidue decomposition. However, much ofthe N contained in urine may be lost due tovolatilization and leaching.

Because the concentration of P in manureis small, animal manures should besupplemented with mineral P fertilizers. Inaddition, ammonia N losses from manureare reduced when mineral P fertilizer isadded. Crops with a large N requirementusually respond well to animal manure(e.g., maize, rice, grasses, and vegetables).

69

than 25 kg N yr-1 excreted by eachcow can be conserved. Soil shouldbe spread in thin layers over the FYMpile to prevent N volatilization. Apply10—50 kg rock phosphate per tonne ofFYM to improve the nutrient balanceand conserve N in the FYM.

Manure quantity

Cattle and water buffalo provide fresh manureequal to about 7.5% of their body weight.Therefore, feedlot cattle of about 150 kgexcrete about 2 t fresh manure over a fatteningperiod of 180 days, or about 4 t fresh manureyr-1.

Do livestock add or remove nutrientsfrom a field?

The inclusion of animals in the farming systemaffects the nutrient cycle. If a stall-fed animalis provided with fodder from one field but theanimal s manure is returned to a different fieldthat is used for vegetable cropping, the nutrientbudget for the whole farm is not affected butnutrient resources will be depleted in thefodder production field and increased in thevegetable field.

Crop residues

Crop residues are usually either used aslivestock fodder, applied as a mulch on thesoil surface, incorporated into the soil, burnedor sold for manufacturing. Returning all cropresidues to the soil helps to replenish SOM.

Effect of burning on crop residues

Burning crop residues is not recommendedas a soil management practice (Plate 2-10b).Burning results in the loss to the atmosphereof almost all the C, N, and S that wascontained in the vegetation. Nitrogen and Sare important nutrients, and carbon isessential for SOM replenishment.

If many land users burn crop residues duringthe same season, this can result inatmospheric haze, with associatedenvironmental health and economic costs. Thedrier the vegetation the smaller the amount of

4 Amount

Recommended rates for animal manureapplication are shown in Table 3-21.

5 Manure quality

Manure quality depends on:

� the animal species,

� age,

� condition,

� diet,

� the nature and amount of litterprovided to stall fed animals, and

� the handling and storage of manurebefore it is spread on the land.

Manure nutrient content is smaller andmanure quality poorer when ruminantsgraze on native forages growing on lowfertility status soils compared with manuresproduced by animals fed on well-fertilized,improved forage supplemented with grainand mineral concentrates.

The methods for reducing N losses inmanure collected in animal shelters are asfollows:

� Use materials such as dried ricestraw, grass clippings, coffee hulls,and sawdust to prepare FYM fromlivestock faeces and urine. Chop orshred the materials (except coffeehulls and sawdust) to make themeasier to spread and increase the rateof decomposition. Spread a 15-cmlayer of litter bedding over the floorspace. Allow manure and urine toaccumulate. Three to four days afterbedding is fully soaked with urine, mixto incorporate the manure. Removethe bedding and store in a pit that isprotected from rainfall to conservenutrient content. Banana leaves makea suitable cover.

� Use the FYM after about 1-2 months.

� Spread loose, dry soil on the floor of acattle shed. When thoroughly soakedwith urine, transfer to a FYM pile. Byregularly repeating this process, more

70

smoke produced by burning. Many land userscontinue to burn residues to reduce labor costsand the time needed for land preparation.Most alternatives to burning crop residues arelabor or time consuming (e.g., composting,surface application).

In any event, farmers without accessto mineral fertilizers will, as a lastresort, continue to burn fallowvegetation to convert availablebiomass into plant availablenutrients.

Mulching

Without a protective mulch cover, microbialactivity in the surface horizon of upland soilsdecreases because the temperature is too highand there is insufficient soil moisture (FigureA-1). Mulch reduces the surface soiltemperature and the loss of water due toevaporation so that soil microbial activity isincreased. An application of about 2 t ha-1

residue can reduce the temperature in thesurface soil layer by up to 10-15 oC. Mulchingalso reduces soil erosion and increases thewater infiltration rate. The rate ofdecomposition is reduced when organicresidues are applied as a surface mulchinstead of incorporated in the soil.

Effect of crop residue quality on Navailability

Legumes and other organic material with anarrow C/N ratio (C/N ratio <15:1) decomposerapidly in humid tropical conditions where soilpH is >5.5 (Table 2-25). However, where the

supply of N in the soil and decomposing plantmaterial is limited, bacteria compete withplants for readily available N (termed Nimmobilization). This results in temporary N-deficiency in soils following the application oforganic materials with a wide C/N ratio (e.g.,rice straw). In the long-term, the N containedin the microbial biomass is released but theshort-term deficiency may affect crop plantgrowth. To increase the rate of decompositionand avoid N immobilization, N fertilizer isapplied together with crop residues thatcontain a small concentration of N (e.g. ricestraw, <1.5% N).

Much of the N in good quality green manure isreleased in 2—4 weeks after application, andleafy legume residues may breakdown sorapidly that crop plants are not able to use allthe N released and N is lost by leaching.

Returning crop residue nutrients to theproper place

Sometimes crop residues or ash are returnedto only a small part of the field (Plate 2-10a).This may result in large soil fertility differencesacross small distances of a few meters. Partsof the field may be severely depleted ofnutrients even though the nutrient budget forthe whole field is zero (Part 2-4).

Farmers sometimes deliberately apply mostof the crop residues to the least fertile part ofthe field, but when large amounts of cropresidues are burned in one place, largeamounts of nutrients may be lost by leaching(Part 2-8). Leaching losses are more likely tooccur on sandy-textured soils.

lairetaM N/C lairetaM N/C

enirU 1:2 nrefnekcarB 1:84

erunamgiP 1:5 wartS 1:08

erunamyrtluoP 1:01 smetsydooW 1:001

)warts+erunam(MYF 1:41 repapsweN 1:002

sdeeW 1:03 draobdraC 1:005

erunamdraymraf=MYF

Table 2-25

Materials with low carbon tonitrogen ratios (C/N), likefarmyard manure,decompose faster thanmaterials with high C/N, suchas woody stems.

71

2-9 Biological soil fertilitymanagement

Use of fallows

Prior to the widespread use of mineralfertilizers, upland farmers relied on the use offallows to regenerate soil fertility. After 1—2cropping seasons, acid upland soils require a7-14 year fallow period to restore soil fertility.During the fallow period, the bush/forestvegetation scavenges for nutrients in the soiland a large pool of nutrients accumulates inthe biomass. The greater the vegetationregrowth, the larger the amount of nutrientsaccumulated in the above ground biomass.Following land clearing, fire is used totransform the above ground biomass into plantavailable nutrients. The more complete theburn, the greater the amount of readilyavailable nutrients in the ash. However,burning results in the loss of most of the Nand S contained in the biomass and othernutrients (P, K, Mg, Ca) may be lost due tosoil erosion and surface runoff unless soilconservation structures are put in placeimmediately after burning. Other benefits fromfallows include breaking pest and diseasecycles and the replenishment of SOM.

However, because of population pressure,fallow periods are now seldom long enoughto completely restore soil fertility and this isthe main reason for the decline in soil fertilityin slash and burn agriculture (Figure A-2).

Various legume covers such as Mucunacoochinchinensis, and Pueraria phaseoloideshave been used successfully as improvedfallow plants to restore fertility in degradedsoils. A large application of phosphate fertilizeris usually required to maximize biomassproduction and biological N2 fixation. Clearly,even improved fallow vegetation does notprovide a direct benefit to the farmer in termsof marketable produce and this is the mainreason why farmers have not adopted thistechnique for soil improvement more widely.Mucuna seed pods are a useful source ofprotein to farmers accustomed to eating thislegume. By removing the pods, however,

farmers are also removing much of the N fixedby the crop, and the residual benefit tosucceeding crops is therefore reduced.

Other species have the capacity to accumulatelarge amounts of P in their above groundbiomass (e.g., Chromolaena odorata) that isreturned to the soil when vegetation is clearedand burned. However, as with all non-legumefallow species, they do not add N, P, K, Mgand Ca to the field, they only recycle nutrientsthat are already in the soil and make themmore available to crops.

Biological nitrogen fixation (BNF)

Legumes can reduce the requirement for Nfertilizers by fixing atmospheric N2 (Plate 2-10d). This means the legume plants demandfor soil N is reduced and soil N is spared foruse by non-legume plants, which cannot fixN. Legumes can fix 50—250 kg N ha-1 yr-1.Biological N2 fixation involves a symbioticrelationship between bacteria (rhizobium orbradyrhyzobium) and a legume plant. Nodulesform on the legume host plant s roots and thebacteria fix N2 from the atmosphere, usingenergy supplied by the host plant. In return,the plant benefits from N produced in thenodule. Legumes vary in the proportion of theirtotal N requirement produced by biological N2

fixation and in some legume crop plants (e.g.,soybean) N removal in the crop product isgreater than the total amount fixed by BNF.

Nodules vary in shape, size, colour, textureand location on the plant. Shape and locationare largely determined by the host plant. Theinside of active nodules is a deep reddishcolour (on cowpea they are sometimes blackin colour). Active nodules turn green as theyage and die. Non-active nodules are white topale green on the inside and do not changecolour.

Native vs. introduced rhizobia

Although plants can nodulate with many typesof rhizobia, only particular strains will increaseplant growth (Table 2-26). Inoculation may benecessary when new legume crops areintroduced, the soil contains very small

72

amounts of rhizobia or the indigenous rhizobiaspecies is not compatible with the legumeplant.

Inoculation methods

A low-cost method for crop inoculation is totake soil from a field where the crop wasrecently grown and found to nodulatesuccessfully and mix this with the seed. Thismethod does not provide a large amount ofrhizobia (compared to a commercial inoculantproduct). It may therefore take several seasonsfor a field planted to the same legume speciesto build a sufficiently large population ofrhizobia in the soil.

Alternatively, commercial inoculants can beused. Legume inoculants are living organismsand should be stored away from direct sunlight.Check that the inoculant product has notpassed the expiration date. Improperlyhandled inoculants can be totally ineffective.Inoculate using the slurry method (mix waterand inoculant and add sugar to improveadhesion between rhizobia and the plantseed). For acid, low P status soils, apply finelyground rock phosphate or lime to theinoculated seed (Table 2-27).

Incorporating N-fixing crops in thesystem

Legume crops contain a large amount ofprotein and can improve the diet of livestock.Legumes deplete the soil of N less rapidly thangrasses, but they do not necessarily increase

puorG sporC

1 naebyoS

2 .ppsangiV

3 sirolfitlum.P,siragluvsuloesahP

4,naebgnum,aepnoegip,aepwoC aicacA

.ppsaiziblA,muignam

5,aidicirilg,ainabses,ardnaillac,.ppsaneacueL

.ppsaicaca

6 .snel,suryhtal,aiciv,musiP

Table 2-26

This table showsinnoculation groups fordifferent crops. For example,rhizobia in Group 1 will notnodulate groundnut, whereasthe same type of rhizobia willnodulate cowpea andmungbean.

the concentration of soil N (a commonmisconception). For example soybeans fix 30-60 kg N ha-1 per crop but about >100 kg N ha-

1 may be removed when the seed is harvested!

Legume shrubs can be planted as soil fertilitytraps in contour strips on sloping land (e.g.,Flemingia macrophylla) and other species(e.g., Calliandra) may be planted as fodderbanks.

Fast-growing, N-fixing trees, such as Gliricidiasepium, Flemingia macrophylla, Acaciamangium, Paraserianthes falcataria, andCalliandra calothyrsus add N to the system.However, except for N-fixing species that addN from the atmosphere, trees do not addnutrients to the system on acid, upland soils!

Deep tree roots can access nutrients from thesubsoil that are inaccessible to food crops.However, subsoil fertility of acid, upland soilsis usually very poor, and trees take up onlysmall amounts of nutrients from deep in thesoil. Other examples of how N-fixing crops canbe integrated into upland systems are shownin Table 3-25.

In the end, biological soil fertility managementis a misleading term since all soil fertilitymanagement techniques involve acombination of chemical, biological andphysical processes. To some readers,biological soil fertility management may implythat sustainable agricultural systems arepossible without the use of external nutrientinputs. In reality, agricultural systems leak, and

73

ytivitcaaibozihrgnitibihnisrotcaF noitadnemmoceR

dnallamsseludon(liosniNfotnuomaegraL)sesaercedNsaezisniesaercni,evitceffe

gk52(NfostnuomallamsylnoylppAah 1- tastnalpporcemugelot)aeru

.gnitnalp

PlioswoL .enozgnitoorporcotrezilitrefPylppA

aepwocroftpecxe,)5.5–0.5Hp<(liosHpwoL .enozgnitoorporcotemilylppA

,edisninoneergdnaegralseludon(oMwoL)evitcanitub

rezilitrefgniniatnoc-oMylppA

Table 2-27 Ways to overcome soil fertility factors that inhibit rhizobial activity and, thus, N-fixation.

htyM tcaFnoitategevwollaF sdda

.liosehtotstneirtun

liosehtotdeddaerastneirtuNdnayellamorfsgninurpni

woregdehpirtsruotnoc.sgninurp

noitategevwollaF snruter yamtahtliosehtotstneirtungnitoorporcehthtaenebmorfdebrosbaneebevah

.enoz

wollafemugelgnixif-N,detaludonylreporpnehWseiceps dda dnayacedtoorhguorhtliosehtotN

.stupnirettildnuorgevoba

deximninworgsemugeLsmetsysgnipporc edivorp otN

.porcnoinapmoceht

semugel.stnemeriuqerNriehtfotrapgnixifyB eraps.stnalpporcgnixif-NnonybekatpurofNlios

sirettamcinagrolioS desaercniotseudiserporcgninruteryb

.lioseht

seudiserporcniliosehtotdenruternobracehT yamebton cinagroliosfonoitelpedehtecalperottneiciffus

.noitisopmocedoteudslioslarutlucirganirettam

liosehtotseudiserporcgninruteR yam etarehtecuder.sliosdetavitlucnirettamcinagroliosniesaercedfo

Table 2-28 Some myths and facts about biological soil fertility management.

nutrients are lost due to erosion, surface runoffand leaching and are removed in cropproducts. Unless removed and lost nutrientsare replaced, nutrient stocks in the system willdecrease and the system will becomeimpoverished and unsustainable. Some of themore common myths relating to biological soilfertility management are discussed in Table2-28.

2-10 Indirect Management Effectson Soil Fertility

Soil conservation and soil fertility

Soil conservation reduces nutrient losses.Without erosion control about 1 cm of topsoilcontaining large amounts of nutrients may belost each year, which means that the entiretopsoil of 15 cm can be lost within onegeneration. It takes several thousand years forthe lost topsoil to form again!

Farmers are usually reluctant to invest in soilconservation if the soil itself is not very fertile,

74

or if they do not have any other incentives fordoing so (e.g., forage supply from plantinggrass conservation strips). Fertilizer nutrientsapplied to the soil are easily lost if proper soilconservation measures are not in place. Theimplementation of effective soil conservationmeasures may occur only slowly over severalseasons. It is especially important to makesure that all fertilizer applied during this periodis not susceptible to erosion or runoff losses.

Major goals of soil erosion control

Soil is lost when soil particles becomedetached from the soil surface and transportedfrom the field by water. The greatestdetachment force is from the direct impact ofrain on soil particles (Plate 2-11f). Detachedparticles and nutrients are then moved bywater to a new location down the slope.Therefore, the major goals of soil erosioncontrol are to reduce the processes ofdetachment and transport of soil particles andnutrients.

Plate 2-11

a) Mulch the soil surface toreduce the amount of soiland nutrients removed insurface runoff.

b) Plant grass strips toreduce nutrient and soillosses from transport in rapidsoil surface water runoff.

c) Leaf rolling in maizeindicates drought stress, dueto poor soil water retentionand possibly K-deficiency.

d) Surface crustingprevents groundnut plantemergence and will result inreduced water infiltration(and greater water runoff)during the growing season.

e) Landslips are commonon sloping land where thesurface vegetation has beenremoved.

f) Columns of soil standdue to the protectionprovided by single leaves.

a b

c d

e f

75

selpicnirP sdohteM

selcitrapliosfotnemhcatedehtecudeR

morfecafrusliosehttcetorP.tcapmipordniartcerid

.)sgnippilcfaeleert,seudiserporcesudnahclumaylppA

ehtfoecrofehtecudeR.pordniar

tatcapmis'pordniarafoecrofehtkaerbotplehsevaeLsuounitnocagniniatniam,nosaersihtroF.ecafruslioseht

.noisoreecuderotplehnacliosehtrevorevoctnalp

tropsnartliosecudeR

retawfodeepsehtecudeR *.

eht,epolsehtregnoleht(epolsehtfohtgnelehtnetrohSehtgnilbuod,elpmaxeenonI.evomnacretawretsaf.)semit2ybssolliosdesaercniepols%9afohtgnel

,seudiserporc,spirtsssargsahcussreirrablacisyhpesU.secarretegdir,sgol,spmutseerteert

secarretlarutanhtiwepolsehtfossenpeetsehtecudeRruotnoc,sreirrabssarg,sllawnoitneterenotsmorfdemrof

.sdnub

.noitartlifniretawesaercnI

erunamlaminaylppadnaliosehthtiwseudiserporcxiMfotnuomaehtesaercninacsihT.erutcurtsliosevorpmiotsnurtahtretawfotnuomaehtecuderdnanoitartlifniretaw

.epolsehtnwodylppA.egallitthgiltuogniyrracybecafrushguoraedivorP

.seudiserporc

:epolsanwodgniwolfretawfodeepsehtgnivlahyB*

,semit46ybdecudersiseirractitahtelcitrapfoezismumixameht)a(

dna,semit4ybdecudersiretawehtforewopevisoreeht)b(

.semit23ybdecudersiretawehtnievomnactahtlairetamfotnuomaeht)c(

Table 2-29 Principles ad methods to reduce soil erosion.

Tillage and soil fertility

Tillage describes the physical preparation ofthe soil before planting and during crop growth.Tillage methods include operations such asploughing and harrowing.

The effects of tillage on soil fertility vary greatlydepending on the soil, crop, and weatherconditions. The major direct effect of tillage ison the position of soil nutrients, microbes, andorganic materials. Major indirect effects of soiltillage on soil fertility include soil moistureavailability, rate of SOM decomposition, andsoil erosion control.

No-tillage

Under a no tillage management system,nutrients (especially P and some K applied asfertilizers), soil microbes, and organic materialsaccumulate near the surface as in a rainforestresulting in greater moisture availability. No-tillage soils generally require larger amountsof N fertilizer, because:

� Fertilizer-N is immobilized in the soil bymicrobes that accumulate in the organiclayer of the soil.

� There is more water movement throughsoil, with greater loss of nitrates.

76

dohtemegalliT segatnavdA segatnavdasiD

)llit-on(egallitoreZetaidemmiehtylno

sienozdees.deraperp

evitaropave,noisoreliossecudeRtneirtundna,ssolMOS,sessolretaw

.ssolrofstneirtunfosloopregralsniatniaM

raenNyllaicepse(ytilibaliavatnalp.egallitmumixamnaht)ecafruseht

nosetalumuccaeudiseRylbissop,ecafrus

.smelborptsepgnisaercnifoesuehtseriuqeR

.sedicitsepdnasedicibreh.dedeenrezilitrefNeroM

eht(egallitmuminiMecafrusdleiferitnedetimilaotdekrow

.)htped

liosniatniamotsplehegallitemoSytivitcalaiborcimsetalumits,noitarea,noitisopmocedlairetamcinagrodna

rofnepoecafrusliosehtspeekdna.noitartlifniretaw

ninahtnoisorelioseroM.egallitorez

egallitmumixaMliospotehtfo%001(.)detrevnirodeximsi

porcfonoitisopmoceddipareroM.seudiser

cinagroliosniesaerceddipareroM.tnetnocrettam

otelbitpecsuslioseroM.ssolnoisore

eraseudiserporcfItonnacyeht,detaroprocni

.hclumsadesueb

Table 2-30 Effects of different tillage practices on soil fertility.

� Denitrification/volatilization may reduce Nefficiency.

Availability, uptake of N and ultimately cropyield may be increased by placing N fertilizerbelow the surface in non-tillage soils.

Conventional tillage

Conventional tillage results in a more evendistribution of nutrients, the soil microbialpopulation, and organic materials in thesurface soil than under zero tillage.

Conventional tillage results in the release ofnutrients for crop uptake by increasing themicrobial decomposition of SOM. This isbecause tillage disrupts the physicalarrangement of the soil, and increasesmicrobial activity because more air penetratesthe soil and a greater surface area of soilorganic residues is exposed to microbialaction.

Water management and soil fertility

For fertilizers to be effective, sufficient watermust be present in the soil for the fertilizernutrients to reach the plant s roots (or vice

versa), nutrient uptake and plant growth (Table2-22). However, water passing through the soilmay remove nutrients by leaching, and waterthat passes over the soil may remove nutrientsby soil erosion and surface runoff.

In most sloping upland farmer s fields, waterinfiltration is insufficient, and surface waterrunoff is too great, and soil conservationmeasures are required not only to reduce soilerosion but also to improve water infiltration.Moisture conservation methods include theconstruction of individual terraces for treecrops (e.g., rubber), ridge and valley tillagesystems where moisture is conserved invalleys, and mulching.

Reduce nutrient content in surfacerunoff

Nutrient losses can be reduced if the flow ofsurface runoff water is slowed down by contourstrips. The contour strips should be plantedwith grasses or shrub vegetation so that theyfunction as nutrient traps by reducing soillosses and increasing the amount of waterinfiltration. Fertilizer nutrient losses are also

77

reduced when fertilizer is incorporated in thesoil.

Reduce nutrient content in water movingthrough the soil profile

The rapid water infiltration rate in properlymanaged upland soils reduces the risk oferosion. However, the surface of upland soilsis often affected by surface crusting whichreduces the water infiltration rate (Plate 2-11d).Nutrient losses due to leaching may be largein sandy textured soils with poor nutrientretention capacity. On such soils, fertilizernutrient losses may be reduced by applyingfertilizer in a larger number of split applications.

75

In this section

Soil and Plant Sampling and Analysis

Soil Chemical Properties for 45 crops

Critical Leaf Nutrient Concentrations for 45 Crops

Nutrient Uptake and Removal for 45 Crops

Properties of Nutrient Sources (Residues and Fertilizers)

General Fertilizer Recommendations and Examples of Field Tests

Management of Micronutrients

Balanced Nutrient Recommendations for 45 Crops

Timing of Fertilizer Applications

Fertilizer Storage

List of Important Legume Species for Acid Upland Soils

English, Indonesian and Latin Names for Important Crop Species

List of Conversion Factors

Glossary of Terms

Part 3Essential information for uplandextension workers

76

3-1 Classification of acid, uplandsoils

The soil classification systems do not use pHvalues explicitly for the definition of soil classesor units. Most FAO soil units, however, andmany taxa of Soil Taxonomy indicate implicitlya narrow range of pH values. The followingsoils are likely to have a soil pH of <5.5:

1. Dystric soil units (e.g., Dystric Gleysols)

2. Soils with an umbric epipedon.

3. Soil groups characterized by low basesaturation (i.e., < 50%) e.g. Acrisols.

4. Thionic soil units.

Thus the following 14 FAO soil units occurringin the tropics are considered acid:

� Thionic, and Dystric Fluvisols� Dystric, and Humic Gleysols

� Orthic, Ferric, and Gleyic Acrisols

� Dystric Nitosols

� Orthic, Xanthic, Humic, Acric, and PlinthicFerralsols, and

� Dystric Histosols.

Some of the Humic and Vitric andosols, Humicand Plinthic Acrisols, Humic Nitosols andRhodic Ferralsols are also acid.

In the Soil Taxonomy, many acid soils canbe found in the following suborders:

� Aquents (Sulfaquents, Hydraquents,Fluvaquents),

� Fluvents (Tropofluvents, Udifluvents),

� Aquepts (Sulfaquepts),

� and in the order of Ultisols (Aquults,Paleudults, kandiudults, kanhapludults),Oxisols, Histosols and Andisols.

In Indonesia, Ultisols occupy almost 70% ofsoils in the Outer Islands (Table A-1 and A-2)

3-2 Soil sampling and testing

The purpose of soil sampling is to open awindow to the soil black box by providingmaterial for soil testing. A representative soil

sample is a prerequisite for successful soiltesting. A layer of soil 20 cm deep contains2000—3,000 t ha-1. A composite sample ofabout 0.5 kg is taken from a field, which mayrepresent <1 ha or ≥30 ha. In the laboratory,about 1 teaspoon of soil (a few grams) is takenfrom the 0.5 kg sample for use in the analyticalprocedure (Figure 3-1). Soils are normallyheterogenous and wide variability can occureven in fields that are apparently uniform.Unless the field sampling procedure isimplemented properly, there is a very bigchance that the soil analytical data will not berepresentative of the field. The procedureinvolved in collecting a representative samplecan be summarised as follows:

1 Check the area to be sampled for notablefeatures (e.g., slope, soil types,vegetation, drainage).

2 Draw a sketch map, and identify andmark the location of sampling points.

Figure 3-1 Soil tests are based on theanalysis of a tiny fraction of the field soil!

▼

▼

▼

3,000 t soil ha-1

10 kg soilcollected

0.5 kg soil tolaboratory

0.001 kg soil used in test

77

3 Avoid sampling across different soil typesand land uses and in distinctive spots(e.g., ash and manure piles, threshingplaces, wet spots).

4 Take a composite sample (25—30individual sub-sample cores) from acircular area, of about 10—20 m diameterbefore moving to another area to besampled.

5 Each sub-sample must be taken to thefull sampling depth.

6 Each composite sample should be clearlyidentified and matched with the sketchmap or field location (use a GPS tospeed up this process and improveaccuracy).

7 Mix composite samples thoroughly and ifnecessary, reduce sample weight bysubdividing (e.g., quartering).

8 Avoid any contamination of samples byother soils, sampling tools, samplingbags, fertilizers, etc.

A field should be tested once every three yearsand samples should be taken just prior toseeding or planting but before fertilizerapplication. In perennial cropping systemssamples should be taken at the same time ofyear. The main objectives of soil testing are:

� to help identify the reasons for poor plantperfomance (diagnostic tool),

� to provide an index of nutrient availabilityor supply in a given soil,

� to predict the response to soilamendments (e.g. lime) and fertilizer,

� to provide a basis for recommendationson the amount of plant nutrients to apply,

� to assist in preparing nutrient budgets ona per field or per farm basis, and

� to evaluate the fertility status of a largersoilscape.

A soil test is a chemical method for estimatingthe nutrient-supplying power of a soil. Althoughplant analyses are extremely valuable indiagnosing nutrient stress, analysis of the soilis essential for determining the supplementalnutrient requirements of a particular crop.Compared to plant analysis, the primaryadvantage of soil testing is its ability todetermine the nutrient status of the soil beforethe crop is planted. However, soil tests are notable to predict the quantity of a nutrient takenup by a crop. To predict the nutrient needs ofcrops, soil test results must be calibratedagainst nutrient uptake and yield in field andglasshouse experiments.

Within given sampling units (i.e., soil areaswhich have been identified as more or lesshomogeneous), random or systematicsampling can be applied. Sampling iscompletely left to the luck of the draw. In somesituations (e.g., tree plantations), systematicsampling (e.g., the soil under every other orevery 5th tree within one sampling unit) couldbe the preferred method.

Plate 3-1 Proper sampling, using theapproriate tools and equipment is anessential part of soil analysis.

78

Table 3-1 Equipment required for working with soils in the field.

ksaT gninoitisoPgnilpmaS

eliforP nodeP liospoT

erusaemepaT X

retemonilC X

TIKSPG X

otohpleiradnapaM X

edaps/levohS X

eoH X

efinkhsuB X X

reguanamledE X X

dnanoisnetxereguanamledEsebut

X

rebburdnalicnep,draobgnitirW X X X X

relpmasliospoT X

)wolley/der(epatretem-2 X

strahc)llesnuM(ruoloclioS X X

efinK X X X X

sneldnaH X X

H(elttobhsaW 2 )O X X X

)tiKegilleH(rotacidniHp X X X

lCH X X X

snepdnasgabelpmas,tekcuB X X X

stopelpmaS X X

gabdleiF X X X X

slaunaM X X X X

79

Table 3-2 Units and methods used for basic soil analysis.

retemaraplioS stinU desudohteM

)retaw(Hp stinuHp H:lios(1:1 2 )O

)lCK(Hp stinuHp )lCKM1:lios(1:1

nobraccinagrO % )kcalBdnayelklaW(noitadixoteW

negortiNlatoT % dohtemlhadlejK

PelbaliavA gkgm 1- ,dohtem)eulbetadbylom(IIyarBretemotohportceps

KelbaegnahcxE gklomc 1- HNM1 4 retemotohpemalf,7Hp,cAO

aNelbaegnahcxE gklomc 1- HNM1 4 retemotohpemalf,7Hp,cAO

aCelbaegnahcxE gklomc 1- HNM1 4 noitprosbacimota,7Hp,cAOretemotohportceps

gMelbaegnahcxE gklomc 1- HNM1 4 noitprosbacimota,7Hp,cAOretemotohportceps

lAelbaegnahcxE gklomc 1- dohtemnoitartitlCKM1

HelbaegnahcxE gklomc 1- dohtemnoitartitlCKM1

egnahcxenoitacevitceffE)CECE(yticapac

gklomc 1- H+lA+gM+aC+aN+KelbaegnahcxE

noitarutaslA % 001x)CEXE÷lAelbaegnahcxE(

dnaS % dohtemettepiP

tliS % dohtemettepiP

yalC % dohtemettepiP

80

Source: Santoso, 1991

Table 3-3 Some chemical characteristics of Indonesian upland soils

ecnivorP.oN

selpmasHp

lAnoitarutas

aC CelbaliavAIyarB,P

% gklomc 1- % gkgm 1-

hecA 89 2.5 82 3.4 6.1 11

artamuShtroN 46 2.5 12 9.1 6.1 11

artamuStseW 42 7.4 54 8.2 1.4 8

uaiR 421 7.4 05 0.3 1.2 9

ibmaJ 48 5.4 06 2.1 8.1 9

ulukgneB 21 7.4 74 1.1 6.2 4

artamuShtuoS 47 7.4 15 4.1 6.1 7

gnupmaL 911 7.4 24 0.1 5.1 7

avaJtseW 841 3.5 31 9.6 3.1 4

natnamilaKtseW 12 3.4 57 7.0 3.2 71

natnamilaKlartneC 93 6.4 26 8.0 1.2 8

natnamilaKtsaE 13 4.4 95 5.2 5.1 03

natnamilaKhtuoS 14 8.4 85 5.1 4.1 6

isewaluSlartneC 12 2.5 64 7.2 4.2 73

isewaluShtuoS 92 2.5 82 7.4 1.2 43

isewaluStsaehtuoS 301 3.5 72 5.3 2.1 11

egarevA – 8.4 54 5.2 0.2 31

81

Table 3-4 Tolerance to lowsoil P status in various crops.

porC PwolotecnareloT

avassaC ******************************

ecirdnalpU *************************

aepwoC ********************

eziaM ***************

tundnuorG *********

naebyoS *****

Table 3-5 Tolerance to Al saturation in various crops.

porC emannitaLwoL

)%04–0(etaredoM)%07–04(

hgiH)%07>(

eziaM syamaeZ X

naebgnuM ataidarangiV X

tundnuorG aegopyhsihcarA X X

aepwoC ataluciugnuangiV X X

naebyoS xamenicylG X

ecirdnalpU avitasazyrO X X

avassaC atnelucsetohinaM X

airaihcarB .ppsairaihcarB X

airateS .ppsairateS X

airalotorC airalatorC X

anucuM sisnenihcnihcocanucuM X X

aidicirilG muipesaidicirilG X

aignimelF atsegnocaignimelF X X

ardnaillaC susryhtolacardnaillaC X X

aocoC oacacamorboehT X

rebbuR sisneilisarbaeveH X X

mlapliO sisneeniugsiaelE X X

82Table 3-6 Critical soil chemical properties for 45 crops.

sporC

P.liavA K.hcxE aC.hcxE gM.hcxE .taslA

gkgm 1- gklomc 1- %

L M H L M H L LM HM H L M H L LM HM H

slaereC

dirbyheziaM 51 52 03 2.0 4.0 4.0 5.0 1 2 2 2.0 5.0 1 03 03 05 06

lacoleziaM 51 52 03 2.0 4.0 4.0 5.0 1 2 2 2.0 5.0 1 03 03 05 06

devorpmieciR 51 52 03 2.0 4.0 4.0 5.0 1 2 2 2.0 5.0 1 03 03 05 06

lacoleciR 51 52 03 2.0 4.0 4.0 5.0 1 2 2 2.0 4.0 8.0 03 03 04 05

sporctooR

avassaC 5 51 51 2.0 3.0 4.0 3.0 5.0 1 1 2.0 3.0 4.0 03 03 08 08

oraT

otatoP 51 53 03 2.0 4.0 4.0 5.0 1 2 2 2.0 4.0 5.0 03 03 05 05

otatopteewS 51 02 02 2.0 3.0 4.0 3.0 1 2 2 2.0 4.0 4.0 03 03 07 07

maY

sporcemugeldooF

snaeB 51 52 03 2.0 4.0 4.0 8.0 1 2 3 2.0 5.0 1 02 52 03 04

aepwoC 01 02 52 2.0 3.0 4.0 4.0 1 2 3 2.0 4.0 5.0 02 52 52 05

tundnuorG 51 52 03 2.0 3.0 3.0 8.0 1 2 3 2.0 4.0 8.0 02 52 03 04

naebgnuM 51 02 52 2.0 3.0 4.0 8.0 1 2 3 2.0 4.0 6.0 02 52 03 04

naebyoS 51 52 03 2.0 4.0 4.0 8.0 1 2 3 2.0 4.0 8.0 02 52 03 03

83Table 3-6 ...continued.

sporC

P.liavA K.hcxE aC.hcxE gM.hcxE .taslA

gkgm 1- gklomc 1- %

L M H L M H L LM HM H L M H L LM HM H

selbategeVtorraC 51 52 03 2.0 4.0 4.0 5.0 1 2 3 2.0 5.0 8.0 02 52 03 04

rebmucuC 51 52 03 2.0 3.0 3.0 4.0 1 2 3 2.0 4.0 5.0 02 52 03 04

tnalpggE 51 52 03 2.0 4.0 4.0 5.0 1 2 3 2.0 5.0 8.0 02 52 03 04

naebgnoL 51 52 03 2.0 4.0 5.0 5.0 1 2 3 2.0 4.0 8.0 02 52 03 04

arkO 51 52 03 2.0 3.0 3.0 4.0 1 2 3 2.0 4.0 5.0 02 52 03 05

noinO 51 52 03 2.0 4.0 5.0 5.0 1 2 3 2.0 5.0 6.0 02 52 03 05

reppepteewS 51 52 03 2.0 4.0 4.0 5.0 1 2 3 2.0 5.0 1 02 52 04 05

nrocteewS 51 52 03 2.0 4.0 4.0 5.0 1 2 3 2.0 5.0 8.0 02 52 04 05

otamoT 51 52 03 2.0 4.0 4.0 5.0 1 2 3 2.0 5.0 6.0 02 52 03 05

sporctiurFodacovA

ananaB 51 02 03 2.0 4.0 4.0 8.0 1 2 3 2.0 4.0 1 02 52 04 05

nairuD 51 02 52 2.0 4.0 4.0 5.0 1 2 3 2.0 4.0 8.0 03 53 05 06

ognaM 51 02 52 2.0 4.0 5.0 5.0 1 2 3 2.0 4.0 8.0 02 52 03 04

egnarO 51 02 52 2.0 3.0 4.0 5.0 1 2 3 2.0 4.0 8.0 03 53 05 06

ayapaP 51 02 52 2.0 3.0 3.0 5.0 1 2 3 2.0 4.0 6.0 03 53 05 06

elppaeniP 51 02 52 2.0 3.0 3.0 5.0 1 1 2 2.0 4.0 6.0 03 53 05 07

natubmaR 51 02 02 2.0 3.0 3.0 5.0 1 1 2 2.0 4.0 6.0 03 53 05 07

nolemretaW 51 02 52 2.0 3.0 4.0 5.0 1 2 3 2.0 4.0 8.0 02 03 04 05

84Table 3-6 ...continued (last).

sporC

P.liavA K.hcxE aC.hcxE gM.hcxE .taslA

gkgm 1- gklomc 1- %

L M H L M H L LM HM H L M H L LM HM H

sporceerT

aocoC 51 52 03 2.0 4.0 5.0 8.0 1 2 2 2.0 5.0 1 02 52 03 05

sevolC 51 02 52 2.0 3.0 4.0 5.0 1 2 3 2.0 4.0 8.0 02 03 04 06

tunocoC 51 02 02 2.0 3.0 3.0 5.0 1 2 2 2.0 4.0 4.0 02 03 05 06

eeffoC 51 02 03 2.0 4.0 5.0 8.0 1 2 3 2.0 4.0 8.0 02 52 04 04

mlapliO 51 02 52 2.0 3.0 3.0 4.0 1 2 2 2.0 3.0 3.0 03 53 05 07

rebbuR 01 02 52 2.0 3.0 3.0 4.0 1 2 2.0 3.0 3.0 03 53 05 07

aeT 01 51 02 2.0 3.0 3.0 4.0 1 1 1 2.0 4.0 6.0 04 54 06 07

sporchsaC

enacraguS 51 02 52 2.0 3.0 4.0 5.0 1 2 2 2.0 4.0 6.0 03 53 05 05

occaboT 51 02 03 2.0 4.0 5.0 8.0 1 2 3 2.0 4.0 6.0 02 52 04 06

secipS

seillihC 51 02 52 2.0 4.0 5.0 6.0 1 2 3 2.0 4.0 8.0 02 52 04 04

reppeP 51 02 52 2.0 3.0 3.0 4.0 1 2 2 2.0 4.0 6.0 03 53 05 05

sporcreddoF

ssarG 51 02 52 2.0 4.0 5.0 8.0 1 2 3 2.0 4.0 8.0 03 53 05 05

semugeL 51 02 03 2.0 4.0 5.0 8.0 1 2 3 2.0 5.0 1 02 52 04 04

85

3-3 Plant sampling and analysis

Plant analysis ( sometimes referred to as leafanalysis) is the determination (usuallychemical analysis) of the amount of eachessential element (or nutrient) in an oven drysample of plant material taken from anominated part of the crop plant at a specifiedtime in the crop cycle. The concentration ofnutrients in plant tissue depends on:

1. the plant part samples,

2. the time of sampling (i.e. the time of day),

3. the time in the cropping cycle (e.g. atflowering, at fruiting), and

4. the plant sampled (each plant maycontain different amounts of particularnutrients).

The main objectives of plant analysis are:

� to confirm a diagnosis made from visualsymptoms,

� to identify hidden hunger where thereare no visual symptoms,

� to locate areas where deficiencies of oneor more nutrients may occur,

� to determine whether applied nutrientshave been taken up by the plant,

� to learn about interactions betweenvarious nutrients, and

� to assess the quality of plant produceand provide a guide to animal and humanhealth.

Various quick tests are used to determine theamount of plant nutrients moving in the sap ofplants. When calibrated, these on-the -spottests can be used to define current nutrientsupply. Similarly as quick soil tests, these fieldtests may be very helpful in the hands of anexpert but can be misleading in inexperiencedhands. These tests should be calibrated forthe crop and conditions where they are used.

3-4 Identification of deficiencysymptoms

The appearance of deficiency symptoms areslightly different for each crop plant andnutrient. There are, however, some genericcharacteristics of deficiency symptoms foreach nutrient (see diagrams below). Thecolours, position on the plant, presence ofchlorosis, and incidence of leaf marginnecrosis are different for each nutrientdeficiency (Table 3-7). All field agronomistsshould attempt to familiarize themselves withnutrient deficiency symptoms for major crops!

Table 3-7 Characteristics of leaf nutrient deficiencies.

tneirtuNnoitisoPtnalpno

?sisorolhCnigramfaeL

?sisorcendnasruoloC

epahsfael

N sevaelllA seY oNsevaelfogniwolleY

snievfaeldna

P sevaelredlO oN oN sehctaphsilpruP

K sevaelredlO seY seY sehctapwolleY

gM sevaelredlO seY oN sehctapwolleY

aC sevaelgnuoY seY oN sevaeldemrofeD

S sevaelgnuoY seY oN sevaelwolleY

eF,nM sevaelgnuoY seY oN sisorolhclanievretnI

oM,aC,uC,nZ,B sevaelgnuoY - - sevaeldemrofeD

86

Location of nutrient deficiency symptoms

87

Potassium deficiency

Location of macronutrient deficiency symptoms

Phosphorus deficiency

Nitrogen deficiency

88

Location of micronutrient deficiency symptoms

S deficiency

Mn, Fedeficiencies

Mg deficiency

B, Zn, Cu,Ca, Modeficiencies

89

Table 3-8 Plant part to be analysed and timing of analysis.

porC traptnalP gnimiT

slaereC

dirbyheziaM bocehtwolebdnaetisoppoedalB gniklistA

lacoleziaM bocehtwolebdnaetisoppoedalB gniklistA

devorpmieciR sevaelreppU gnirewolferofeB

lacoleciR sevaelreppU gnirewolferofeB

sporctooR

avassaC sevaetsegnuoylht5dnaht4 gnitnalpretfashtnom4

oraT edalbfaeltsegnuoydn2 tsevrahtA

otatoP sevaeldepolevedylluF gnirewolftA

otatopteewS htworgdiM faelerutamtsegnuoY

maY eloitephtiwfaeL gnitnalpretfahtnomdr3

semugeldooF

naeB sevaeldepolevedylluF gnirewolftA

aepwoC toohselohW gnirewolfylraetA

tundnuorG .sevaeldepolevedylluF gnirewolftA

naebgnuM toohselohW gnirewolftA

naebyoS .sevaeldepolevedyllufreppU gnirewolftA

selbategeV

torraC toohselohW doirepporcdimtA

rebmucuC .sevaeldepolevedylluF gnirewolftA

tnalpggE ht5 ltsegnuoy fae gnitnalpretfasyad06

naebgnoL faelerutamgnuoY gnirewolfylraetA

arkO

noinO edalberutamtsegnuoY gnipporcdimtA

reppepteewS sevaeldepolevedylluF gnipporcdimtA

nrocteewS spitmorffaelht5 gnipporcdimtA

otamoT sevaeldepolevedylluF testiurftA

90

Table 3-8 ...continued.

porC traptnalP gnimiT

sporctiurF

odacovA sevaeldepolevedylluF hsulfporctA

ananaB sedalbfaeldepolevedylluf,gnuoyfospirtS htworgevitcagniruD

nairuD sevaeldepolevedylluf,gnuoY seertevitcudorP

ognaM hsulftnerrucfoesabmorffaelht5 tsevrahretfA

egnarO sehcnarbgnuoyfosevaeldepolevedylluF seertevitcudorP

ayapaP faelerutamtsegnuoyfoeloiteP gnirewolftA

elppaeniP faelerutamtsegnuoYroirphtnom1dna3,6tA

noitcudnirewolfot

natubmaR sevaeldepolevedyllufgnuoY seertevitcudorP

nolemretaW sevaeldepolevedyllufgnuoY doirepporcdimtA

sporceerT

aocoC sevaeldepolevedyllufgnuoY seertevitcudorP

sevolC seerterutam,gnuoY seertevitcudorP

tunocoCylluftsrifehtmorfgnitnuoc(faelht41

)faeldeneposeertevitcudorP

eeffoCsehcnarbnosevaeldepolevedylluF

seirrehcgniyrracfonoitacilppaerofeB

srezilitref

mlapliOylluftsrifehtmorfgnitnuoc(faelht71

)faeldeneposeertevitcudorP

rebbuR dlosyad051–09,sevaeldedahS seertevitcudorP

aeT sdubsulpsevael2 gnitnalptA

sporchsaC

enacraguS )DVT(faeLretfashtnom6–3

gnitnalp

occaboT sevaeldepolevedylluF doirepporcdiM

secipS

seillihC sevaelerutamgnuoY gnitiurfylraE

reppeP sevaeldepolevedylluf,gnuoY stnalpevitcudorP

sporcreddoF

ssarG mc5evobatoohselohW gnirewolftsriftA

semugeL toohselohW gnirewolftA

91Table 3-9 Critical leaf nutrient concentrations for N, P and K in 45 crops.

porC)MD%(N )MD%(P )MD%(K

L M H L M H L M H

slaereC

dirbyheziaM 9.2< 5–3 5> 52.0< 6.0–3.0 6.0> 5.1< 6.2–8.1 3>

lacoleziaM 5.2< 4–3 4> 52.0< 5.0–3.0 5.0> 3.1< 0.3–7.1 3>

devorpmieciR 5.2< 4–3 5.4> 2.0< 4.0–2.0 4.0> 2< 5.4–3 5.4>

lacoleciR 5.2< 4–3 5.4> 2.0< 5.0–2.0 5.0> 2< 5.4–3 5.4>

sporctooR

avassaC 5.4< 5.5–5.4 5.5> 3.0< 5.0–3.0 5.0> 1< 0.2–5.1 0.2>

oraT 7.3< 0.5–9.3 5.5> 33.0< 9.0–5.0 1> 5.4< 6–5 6>

otatoP 5.1< 5–3 5.6> 2.0< 6.0–4.0 6.0> 2< 5–3 7>

otatopteewS 5.2< 4–3 5> 21.0< 2.0 3.0> 8.0< 5.1–0.1 2>

maY 5.1< 0.2–5.1 5.2> 51.0< 2.0 3.0> 5.1< 5.2–5.1 5.2>

semugeldooF

snaeB 2< 5-3 5> 2.0< 5.0–2.0 5.0> 2< 3–2 3>

aepwoC 2< 4-3 5> 2.0< 5.0–2.0 5.0> 2< 3–2 3>

tundnuorG 2< 4-3 5> 2.0< 5.0–2.0 5.0> 2< 3–2 5.3>

naebgnuM 2< 4-3 5> 2.0< 5.0–2.0 5.0> 2< 3–2 5.3>

naebyoS 2< 5-3 5> 2.0< 5.0–3.0 6.0> 2< 3–2 5.3>

92Table 3-9 ...continued.

porC)MD%(N )MD%(P )MD%(K

L M H L M H L M H

selbategeV

torraC 2< 3-2 5.3> 2.0< 4.0–3.0 5.0> 2< 3–2 4>

rebmucuC 2< 0.4-5.2 5> 2.0< 5.0–3.0 6.0> 2< 5.4–5.2 5.5>

tnalpggE 2< 0.3–5.2 4> 2.0< 5.0–3.0 6.0> 2< 4–2 4>

naebgnoL 5.2< 5.3–0.3 4> 2.0< 5.0–5.0 6.0> 2< 3–2 4>

arkO 5.2< 5.3–0.3 4> 2.0< 5.0–5.0 6.0> 2< 3–2 4>

noinO 2< 3–2 3> 2.0 4.0–2.0 4.0> 2< 3–2 3>

reppepteewS 3< 4–3 5.4> 2.0< 5.0–3.0 6.0> 3< 5–4 5>

nrocteewS 5.2< 5.3–5.2 5.3> 2.0< 6.0–3.0 6.0> 2< 5.3–5.2 4>

otamoT 0.3< 5.4–5.3 0.5> 3.0< 8.0–3.0 9.0> 2< 5.4–5.2 5>

sporctiurF

odacovA 5.1< 0.2–6.1 5.2> 1.0< 3.0–1.0 3.0> 3.0< 0.2–5.0 3>

ananaB 0.3< 5.3–0.3 5.3> 1.0< 2.0–1.0 3.0> 3< 5–4 5>

nairuD 0.2< 3–2 3> 2.0< 3.0–2.0 3.0< 2< 3–2 4>

ognaM 5.1< 3-2 3> 2.0< 3.0–2.0 4.0> 3< 4–3 5>

egnarO 0.2< 3–2 5.3> 51.0 3.0–2.0 3.0> 1< 2–1 2>

ayapaP 5.1< 0.2–5.1 5.2> 1.0< 3.0–1.0 3.0> 8.0< 2–1 2>

elppaeniP 5.1< 0.2–5.1 2> 51.0< 2.0 52.0> 8.1< 3–2 5.3>

natubmaR 5.1< 3–2 3> 2.0< 3.0–2.0 4.0> 0.2< 3–2 4>

nolemretaW 8.1< 3–2 3> 2.0< 4.0–2.0 5.0> 2< 3–2 5.3>

93Table 3-9 ...continued.

porC)MD%(N )MD%(P )MD%(K

L M H L M H L M H

sporceerT

aocoC 2< 5.2-0.2 5.2> 1.0< 2.0–1.0 2.0> 1< 3–1 3>

sevolC <

tunocoC 8.1< 5.2–0.2 5.2> 1.0< 51.0–21.0 71.0> 8.0< 5.1–0.1 5.1

eeffoC 5.2< 5.3–5.2 5.3> 1.0< 2.0–1.0 2.0> 5.1< 5.2–0.2 5.2>

mlapliO 5.2< 0.3–5.2 0.3> 51.0< 81.0–71.0 2.0> 1< 3.1–0.1 3.1>

rebbuR 0.3< 5.3–0.3 5.3> 2.0< 52.0–22.0 52.0> 3.1< 6.1–3.1 7.1>

aeT 5.3< 5–4 5> 3.0< 5.0–3.0 6.0> 5.1< 5.2–5.1 5.2>

sporchsaC

enacraguS 2< 3–2 3> 2.0< 3.0–2.0 3.0> 1< 2–1 2>

occaboT 2< 5.2–0.2 3> 2.0< 4.0–2.0 5.0> 2< 4–2 4>

secipS

seillihC 5.2< 4–3 5.4> 2.0< 4.0–3.0 5.0> 5.2< 4–3 5.4>

reppeP 5.2< 5.3–0.3 5.3> 51.0< 2.0 2.0> 5.2< 4–3 5.4>

sporcreddoF

ssarG 5.1< 3–2 3> 2.0< 4.0–2.0 4.0> 2< 5.3–0.2 5.3>

semugeL 3< 5–3 5> 2.0< 5.0–3.0 6.0> 0.2< 0.4–5.2 4>

94Table 3-10 Critical leaf nutrient concentrations for Ca, Mg and S in 45 crops

porC)MD%(aC )MD%(gM )MD%(S

L M H L M H L M H

slaereC

dirbyheziaM 3.0< 0.1–3.0 0.1> 51.0< 6.0–2.0 6.0> 51.0< 3.0–2.0 3.0>

lacoleziaM 2.0< 0.1–2.0 0.1> 51.0< 5.0–2.0 6.0> 51.0< 3.0–2.0 3.0>

devorpmieciR 2.0< 6.0–2.0 6.0> 2.0< 4.0–2.0 5.0> 51.0< 52.0–2.0 3.0>

lacoleciR 51.0< 6.0–2.0 6.0> 51.0< 3.0–51.0 3.0> 1.0< 2.0 52.0>

sporctooR

avassaC 6.0< 8.0–6.0 0.1> 52.0< 4.0–3.0 5.0> 52.0< 3.0–52.0 3.0>

oraT 0.2< 0.4–6.2 5.4> 51.0< 52.0–71.0 3.0> 62.0< 33.0–72.0 53.0>

otatoP 5.0< 5.1–5.0 0.2> 1.0< 5.0–2.0 6.0> 52.0< 4.0–52.0 4.0>

otatopteewS 2.0< 4.0–2.0 8.0> 51.0< 3.0–2.0 4.0> 1.0< 3.0–2.0 3.0>

maY 5.0< 5.1–5.0 5.2> 51.0< 3.0–2.0 40> 1.0< 2.0–51.0 3.0>

semugeldooF

snaeB 5.0< 0.2–5.0 0.2> 3.0< 7.0–5.0 8.0> 51.0< 52.0 4.0>

aepwoC 5.0< 5.1–5.0 0.2> 2.0< 6.0–3.0 8.0> 31.0< 52.0–81.0 3.0>

tundnuorG 0.1< 0.2-5.1 5.2> 2.0< 6.0–3.0 8.0> 22.0< 7.0–5.0 7.0>

naebgnuM 0.1< 0.2–0.1 5.2> 2.0< 7.0–3.0 8.0> 2.0< 53.0–52.0 4.0>

naebyoS 5.0< 5.1–6.0 0.2> 2.0< 7.0–3.0 8.0> 51.0< 53.0 4.0>

95Table 3-10 ...continued.

porC)MD%(aC )MD%(gM )MD%(S

L M H L M H L M H

selbategeV

torraC 8.0< 0.2–0.1 0.2> 3.0< 6.0–4.0 8.0> 52.0< 3.0 8.0>

rebmucuC 0.3< 0.6–0.4 0.8> 3.0< 0.1–5.0 0.1> 52.0< 7.0–4.0 0.1>

tnalpggE 5.0< 0.2–0.1 0.2> 3.0< 8.0–3.0 8.0> 2.0< 5.0–4.0 8.0>

naebgnoL 5.0< 0.2.0–5.0 0.2> 3.0< 6.0–4.0 7.0> 2.0< 3.0–2.0 5.0>

arkO 5.2< 0.4–0.2 0.5> 3.0< 7.0–5.0 7.0> 2.0< 4.0–3.0 5.0>

noinO 5.0< 5.1–6.0 5.1> 52.0< 5.0–3.0 5.0> 3.0< 0.1–5.0 0.1>

reppepteewS 4.0< 8.0–4.0 0.1> 3.0< 6.0–3.0 8.0> 2.0< 3.0 4.0>

nrocteewS 4.0< 6.0–4.0 8.0> 1.0 2.0–1.0 5.0> 2.0< 3.0–2.0 3.0>

otamoT 0.2< 0.4–0.3 0.4> 3.0< 6.0–3.0 8.0> 4.0< 5.0 0.1>

sporctiurF

odacovA 1< 3–1 3> 2.0< 5.0–3.0 8.0> 2.0< 6.0–2.0 8.0>

ananaB 5.0< 3.1–8.0 3.1> 3.0< 4.0–3.0 4.0> 2.0< 52.0–2.0 3.0>

nairuD 2< 4–2 5> 2.0< 4.0–2.0 4.0> 2.0< 4.0–3.0 5.0>

ognaM 2< 4–2 5> 2.0< 4.0–2.0 4.0> 2.0< 3.0–52.0 53.0>

egnarO 2< 6–3 8> 2.0< 6.0–3.0 7.0> 51.0< 2.0–51.0 4.0>

ayapaP 1< 3–1 4> 1.0< 4.0–3.0 5.0> 2.0< 3.0–2.0 4.0>

elppaeniP 3.0< 6.0–3.0 8.0> 2.0< 3.0–2.0 4.0> 31.0< 54.0–22.0 6.0>

natubmaR 2< 4–2 5> 2.0< 4.0–2.0 4.0> 2.0< 3.0–2.0 5.0>

nolemretaW 2.1< 0.3–5.1 5.3> 3.0< 8.0–4.0 8.0> 2.0< 3.0–52.0 3.0>

96Table 3-10 ...continued (last).

porC)MD%(aC )MD%(gM )MD%(S

L M H L M H L M H

sporceerT

aocoC 3.0< 8.0–3.0 8.0> 3.0< 6.0–4.0 8.0>

sevolC 3.0< 8.0–4.0 0.1> 2.0< 3.0–2.0 3.0> 51.0< 52.0–2.0 3.0>

tunocoC 3.0< 5.0–3.0 6.0> 2.0< 3.0–2.0 4.0> 51.0< 52.0–2.0 3.0>

eeffoC 8.0< 5.1–0.1 5.1> 3.0< 5.0–3.0 5.0> 1.0< 2.0–1.0 2.0>

mlapliO 3.0< 7.0–3.0 0.1> 2.0< 4.0–2.0 7.0> 2.0< 4.0–2.0 6.0>

rebbuR 3.0< 6.0–4.0 0.1> 2.0< 22.0 52.0> 51.0< 3.0–2.0 3.0>

aeT 3.0< 6.0–4.0 8.0> 2.0< 4.0–2.0 4.0> 51.0< 3.0–2.0 4.0>

sporchsaC

enacraguS 2.0< 4.0–2.0 4.0> 51.0< 3.0–2.0 3.0> 31.0< 3.0–2.0 4.0>

occaboT 8.0< 0.2–0.1 5.2> 3.0< 6.0–4.0 8.0> 51.0< 3.0–52.0 5.0>

secipS

seillihC 8.0< 5.1–0.1 2> 3.0< 5.0–4.0 5.0> 51.0< 3.0–2.0 4.0>

reppeP 8.0< 0.2–0.1 5.2> 3.0< 5.0–4.0 5.0> 2.0< 3.0 4.0>

sporcreddoF

ssarG 2.0< 5.0–2.0 6.0> 2.0< 5.0–2.0 5.0> 1.0< 4.0–1.0 4.0>

semugeL 41.0< 52.0 53.0>

97Table 3-11 Nutrient uptake and removal in 45 crops.

porC tcudorP dleiYdnuorgevoba(ekatpulatoT

)ssamoib)dleiyporc(lavomeR

L H N P K aC gM S N P K aC gM S

aht 1- ahgk 1-

slaereC

dirbyheziaM niarG 5.4 5.4 511 02 57 9 61 21 07 31 71 2 4 6

lacoleziaM niarG 5.2 5.2 56 11 24 5 9 7 04 7 01 1 2 3

devorpmieciR niarG 4 4 09 31 801 11 01 4 06 11 11 1 4 3

lacoleciR niarG 2 2 54 7 45 6 5 2 03 5 5 1 2 1

sporctooR

avassaC stooR 21 02 59 51 19 05 51 01 53 9 05 8 4 4

oraT srebuT 01 02 031 02 331 23 71 21 06 11 85 6 7 5

otatoP srebuT 01 51 08 31 001 41 9 01 04 5 45 4 5 5

otatopteewS srebuT 8 5 06 9 17 7 6 5 03 4 24 3 4 2

maY srebuT 51 52 08 31 19 91 6 5 03 8 05 4 2 2

semugeldooF

snaeB snaeB 2 3 081 02 611 63 63 02 58 9 24 6 4 3

aepwoC niarG 1 1 08 7 24 12 21 01 55 5 12 4 4 6

tundnuorG niarG 2 3 051 31 17 46 12 02 08 8 21 4 4 3

naebgnuM niarG 5.0 1 09 7 17 12 21 01 55 4 71 4 3 2

naebyoS niarG 1 2 09 8 21 51 6 01 57 6 32 4 4 3

98Table 3-11 ...continued.

porC tcudorP dleiYdnuorgevoba(ekatpulatoT

)ssamoib)dleiyporc(lavomeR

L H N P K aC gM S N P K aC gM S

aht 1- ahgk 1-

selbategeV

torraC stooR 01 02 09 31 521 34 21 01 06 9 57 7 4 2

rebmucuC tiurF 01 02 54 7 85 51 6 5 52 3 52 4 3 2

tnalpggE tiurF 01 02 001 11 521 92 81 01 03 6 73 2 4 3

naebgnoL snaeB 8 51 021 11 85 92 9 01 55 5 52 6 2 2

arkO tiurF 8 51 051 22 19 12 12 01 06 01 05 31 7 2

noinO sbluB 02 03 001 71 19 12 21 02 04 7 24 6 3 4

reppepteewS tiurF 01 02 07 9 57 34 21 02 04 52 24 7 4 2

nrocteewS sboC 01 02 041 22 941 52 21 01 07 7 57 6 3 2

otamoT tiurF 01 02 09 9 611 92 21 01 04 5 05 6 4 2

sporctiurF

odacovA tiurF 01 01 06 11 66 63 81 01 02 4 73 2 5 1

ananaB tiurF 02 03 022 53 097 971 24 02 06 7 141 7 8 6

nairuD tiurF 6 21 08 51 611 34 42 02 03 5 05 4 6 3

ognaM tiurF 6 51 08 9 38 75 63 01 03 4 33 7 4 2

egnarO tiurF 01 02 031 31 051 34 21 51 03 4 24 11 4 2

ayapaP tiurF 01 02 06 9 57 12 6 01 52 4 22 6 2 2

99Table 3-11 ...continued.

porC tcudorP dleiYdnuorgevoba(ekatpulatoT

)ssamoib)dleiyporc(lavomeR

L H N P K aC gM S N P K aC gM S

aht 1- ahgk 1-

sporctiurF

elppaeniP tiurF 03 06 081 22 082 27 42 02 04 7 19 11 5 2

natubmaR tiurF 5 51 08 31 57 34 42 01 03 4 52 11 5 2

nolemretaW tiurF 01 02 08 71 001 23 12 01 03 9 73 6 7 2

sporceerT

aocoC snaeB 1 2 041 51 851 411 84 01 03 7 71 2 4 2

sevolC sevolC 3.0 1 07 31 19 34 42 01 01 1 21 2 2 1

tunocoC stuN 6 01 061 31 42 68 24 52 07 71 19 41 81 21

eeffoC snaeB 1 2 021 71 941 75 03 02 04 4 24 5 5 6

mlapliO hcnuB 02 03 091 62 752 34 06 03 57 31 001 41 12 51

rebbuR xetaL 5.0 5.1 05 7 14 11 6 01 02 5 52 4 5 2

aeT aeT 5.0 5.1 021 51 66 92 9 01 04 5 12 6 2 2

sporchsaC

enacraguS enaC 06 001 011 62 141 75 63 03 09 51 19 12 42 02

occaboT sevaeL 1 2 09 31 941 75 42 02 05 8 57 41 21 5

100Table 3-11 ...continued (last).

porC tcudorP dleiYdnuorgevoba(ekatpulatoT

)ssamoib)dleiyporc(lavomeR

L H N P K aC gM S N P K aC gM S

aht 1- ahgk 1-

secipS

seillihC sdoP 2 3 061 51 381 63 81 01 06 7 66 6 3 2

reppeP snroc/P 1 3 081 31 331 92 21 51 06 5 24 4 2 2

sporcreddoF

ssarG MD 4 8 081 22 661 34 03 52 021 31 521 41 51 21

semugeL MD 5 01 003 53 662 701 24 04 042 82 612 97 03 02

101

Table 3-12 Nutrient content of manures and residues commonly available in Indonesia.

lairetaMretaW)%(

C N P K aC

lairetamhserf%

seceafnamuH – – 0.1 2.0 3.0 –

seceafelttaC – – 3.0 1.0 1.0 –

seceafgiP – – 5.0 2.0 4.0 –

erunamelttachserF 06 01–8 6.0–4.0 2.0–1.0 6.0–4.0 4.0–2.0

erunamelttacdetsopmoC 53 53–03 5.1 2.1 1.2 2

erunamdraymraF 05 - 0.1 8.0 2.1 8.0

erunamtaoG 05 - 8.0 7.0 5.1 8.0

erunampeehS 05 - 0.1 7.0 5.1 7.1

erunamgiP 08 01–5 0.1–7.0 3.0–2.0 7.0–5.0 2.1

erunamyrtluoP 55 51 6.1–4.1 8.0–52.0 8.0–7.0 3.2

tsopmocegabraG 04 61 6.0 2.0 3.2 1.1

egdulsegareweS 05 71 6.1 8.0 2.0 6.1

ekacretlifenacraguS 08–57 8 3.0 2.0 60.0 5.0

ekacnaebrotsaC 01 54 5.4 7.0 1.1 8.1

ttneirtungk 1- 01xtnetnoctneirtun%=erunamhserf

102Table 3-13 Basic characteristics of fertilizers commonly available in Indonesia.

emaN alumroF lairetamwaRwarfoecruoS

slairetamssecorP

aerU – HN(OC 2)2 HN 3 OCdna 2 erehpsomtA'elcyceRlatoT'dna'laitraP','hguorhTecnO'

noitcaerhcsoB-rebaHnodesab,sessecorp

foetahpluSainomma

AS HN( 4)2 OS 4

-yblacimehCstcudorp

HN 3 OSaC, 4 OC, 2

muinommamuiclaCetartin

HfonoitarutaS 2 OS 4 HNhtiw 3 anueL,ssecorp

muiclaCetartinmuinomma

NACHN 4 ON 3 +

OCaC 3

-yblacimehCtcudorp

ONH 3 HN, 3,OCaC 3 ON(aC/ 3)2

HNfonoitsubmoC 3 OCaC+ 3 ADDO,ssecorp

repuselpirTetahpsohp

PST H(aC 2 OP 4)2 lairtserreT H,kcorP 3 OP 4

htiwskcorPdezirevlupfotnemtaerTdicacirohpsohp

muinommaiDetahpsohp

PAD HN( 4)2 OPH 4

-yblacimehCstcudorp

HN 3 H, 3 OP 4

HN+yrrulsdica(noitcaerssecorp-teW 3 taO511 O )C

kcoretahpsohP RP aC 01 OP( 4)6F2 lairtserreT eroetahpsohP gnidnirgdnanoitacifiruP

63PS

hsatopfoetairuM POM lCK enirtsucal-eniraM lCgM,lCK 2 .cte,lCaN, noitazillatsyrc,noitatolf,noitulossidlamrehT

etiniebgnaL - K2 OS 4. OSgM 4 enirtsucal-eniraM tlaskcoR noitalunarg,noitagergeS

etireseiK - OSgM 4. H2O enirtsucal-eniraM KtlaskcoR 2 OS(gM 4)2

,snoitacifenebcitatsortcele,noitagergeSnoitalunarg

etimoloD - OC(gMaC 3)2 stnemideseniraM etimolod/eticlaC gnidnirg,noitagergeS

muidos(etaroB)etarob

- aN 2BsO 31. H4 2O enirtsucaL xarob,etixelU stlasenirtsucaldetatipicerpfonoitagergeS

etahplusreppoC - OSuC 4. H5 2O enirtsucal-eniraM SeFuC 2 SeF, 2 SeFuC, 4 H+stcudorptlemuCfonoitcaeR 2O

103Table 3-14 Nutrient content of fertilizers commonly available in Indonesia.

rezilitreF noitaiverbbA N P2O5 K2O OgM OaC S srehtOgniyfidicA

?lios

aerU - 64 yletaredoM

edirolhcmuinommA CA 52 lC66 yletaredoM

etartinmuinommA NA 43 yletaredoM

etartinmuiclaC NC 51 5.2 62 yletaredoM

etahplusmuinommA SA 12 42 ylgnortS

etahpsohpmuinommaonoM PAM 11 55–84 5.0 2 3–1 thgilS

etahpsohpmuinommaiD PAD 12–81 35–64 5.1–1 thgilS

etahpsohpkcoR PR 14–52 05–52 oN

etahpsohpmuisengamdesuF PMF 51–21 51–01 61–21 oN

etahpsohprepuselgniS PSS 22–61 41–11 oN

etahpsohprepuselbuoD 63PS 63–23 oN

etahpsohprepuselpirT PST 35–44 5.0 91–21 5.1–1 oN

edirolhcmuissatoP lCK/POM 26–06 lC74 oN

etahplusmuissatoP POS 35–05 81–71 oN

etartinmuissatoP NK 31 44 5.0 5.0 2.0 oN

etireseiK seiK 72 22 oN

etiniebgnaL gMKS 22 81 22 oN

etimoloD LMG 22–01 54–53 oN

)eticlac(emilirgA emilgA 74 oN

104Table 3-14 ...continued.

rezilitreF noitaiverbbA N P2O5 K2O OgM OaC S srehtOgniyfidicA

?lios

muspyG – 03–22 61–31 oN

51-51-51KPN – 51 51 51 oN

8-61-61KPN – 61 61 8 1 oN

12-31-31KPN – 31 31 12 oN

+)gM(2[+71-21-21KPN])ET(stnemeleecarT

– 21 21 71 2-unorciM

stneirtoN

)gM(4+6-51-51KPN – 51 51 6 4 oN

105

Table 3-15 Characteristics of major rock phosphate sources available in Indonesia.

yrtnuoC ecalPlatoT

AC%2elbulos

AF%2elbulos

OaC

P% 2O5 %

ailartsuA dnalsIsamtsirhC 43 21 21 63

anihC nannuY 53 41 8 44

aisenodnI kiserG 82 4 .a.n 34

nadroJ assaHlE 33 11 51 05

occoroM abgiruohK 33 11 71 15

aisinuT asfaG 03 9 22 74

ASU adirolF 13 5 7 64

ASU aniloraChtroN 53 31 52 94

dicacimrof=AF,dicacirtic=AC

106

3-5 General fertilizerrecommendations for Indonesianacid, uplands

� Low P soils - most acid, upland soils thathave not previously been fertilized with atleast 25-50 kg P ha-1 yr-1. If pH < 5.5,apply either 1 t rock phosphate ha-1, or ifpH ≥ 5.5, apply 400-500 kg SP-36 ha-1

(one-time application).

� Low K soils - most acid, upland soils thathave been cropped for several years, butwhere K removal in crop products hasnot been replenished with crop residue orfertilizer K. Apply about 25 kg K ha-1 (in 3t air-dried cow manure ha-1 or 50 kg KClha-1).

� Low Ca soils - a limiting factor on someacid, upland soils, depending on the cropgrown.

� Low Mg soils - deficient on many acid,upland soils that have been cropped forseveral years, but where Mg removal incrop products has not been replenishedwith crop residue or fertilizer Mg. Applyabout 20 kg Mg ha-1 (or a one-timeapplication of 3 t air-dried cow manureha-1 or 125 kg kieserite ha-1)

� Low S soils - some acid, upland soils aredeficient, especially where much of thecrop residue has been removed andcrops with a large S requirement (oilseed crops like soybean) are planted.

3-6 Examples of simple fieldtests

1. Compare two different timings offertilizer (e.g., all at planting comparedwith split application).

This experiment can be useful if it can showfarmers that they may save time by reducingthe amount of times that they apply fertilizeror they may even be applying fertilizer too late.For example, some farmers may apply Pfertilizer at 2-3 weeks after planting. This maybe in addition to a P application at planting orit may be the only application. P fertilizer is

usually best applied at planting, especially forannual crops.

Recommended treatment: apply all P fertilizerat planting.

Farmer practice : current practice. Somefarmers may wait until they are sure that thecrop germinates before they fertilize to reducerisk, but they may increase risk by not fertilizingon time.

2. Compare the method used toapply fertilizer (e.g., comparing shallowincorporation with surface application).

In situations where there is a large potentialfor loss of surface-applied fertilizer, test theeffect of incorporating fertilizer on fertilizerefficiency. This could result in larger yields forthe incorporated versus surface-appliedtreatment. Alternatively, reduce the fertilizerdose slightly for the incorporated treatment toallow for greater fertilizer efficiency.

3. Compare two differentcombinations of nutrients (e.g.,comparing 100-50-25 with 75-50-50.Both use total of 175 kg of fertilizer)

The farmer may be using too much of onenutrient and not enough of others (e.g., toomuch N and P but not enough K). Test theeffect of decreasing the N dose and increasingthe amount of k applied. Try to end up with thesame cost, but at different nutrientcombinations.

4. Compare the effect of organicmaterial management (e.g., compareremoving all rice straw with returning allof the rice straw and/or 100 urea, 50SP-36, 25 KCL vs. 100 urea, 50 SP-36,1 T cow dung ha-1).

This can demonstrate how by returning all ofthe residue to the field, fertilizer costs can bereduced.

107

5. Compare fertilizer applicationrates (e.g., compare 100-50-50 with 50-75-75)

If the farmer is already fertilizing efficiently,consider increasing the fertilizer applicationrate in order to increase production.

3-7 Understanding FertilizerNutrient Recommendations

Removal

Crop production can only be sustained whennutrients removed in the harvested parts ofthe crop are replaced. The amount of nutrientsrequired to replace removal in crop productsis shown in Table 3-11. Fertilizer nutrientrecommendations are shown in Table 3-20 nd3-21. The amount of external nutrient inputsrequired by a crop depends on a number offactors:

� the total nutrient uptake required toachieve the target yield (related tobiomass production and the nutrientconcentration in the biomass),

� the amount of nutrients supplied by thesoil, and

� the efficiency with which the crop plantrecovers nutrients from external nutrientinputs (e.g., manure, mineral fertilizer).

Clearly, larger yields require larger amountsof nutrients to grow them and to replenish thenutrients exported in crop products.

For example, small yields (1 t paddy ha-1) of atraditional local rice variety can possibly besustained with very small applications ofaround 5-10 kg K20 ha-1, provided the ricestraw is returned to the field. By contrast, amodern high yielding variety (5 t paddy ha-1)

removes about 160 kg K20 from the soil if thestraw and grain are removed from the field.,

It is therefore very important that fertilizerrecommendations take account of the amountof nutrients removed or returned in differentparts (e.g., grain, straw) of the crop concerned.

About 3 kg K20 t-1 is removed in rice grain butnearly 30 kg K20 ha-1 is removed (or returnedto the field) with each tonne of harvested straw.Clearly, if chaff is returned to the field afterthreshing and hulling and rice bran afterpolishing rice, a very small amount of K isrequired to replenish the amount of K exportedin the final grain product.

The amount of nutrients removed in cropproducts can vary greatly between cropvarieties and species due to differences in:

� yield potential,

� the nature of the crop products, and

� the nutrient content of harvested parts.

For example, about 140 kg K20 ha-1 may beremoved with a yield of 20 t banana bunchescompared to only 40 kg K20 ha-1 with similaryields of papaya or water melon fruits.

Uptake

In addition to nutrient removal in crop yield,fertilizer nutrient recommendations must besupplied in sufficient quantity to satisfy the totalnutrient uptake required to achieve the targetyield.

At similar yield levels of banana, oil palm andpapaya, the amount of nutrients contained inthe harvested biomass is much larger inbanana than oil palm or papaya (Table 3-16).

Table 3-16 Amount of Kremoved in three differentcrops

porCdleiYaht( 1- )

straPtnuomAahKgk( 1- )

ananaB 02 strapdnuorgevobA 006

mlapliO 02 sevael2+sehcnuB 002

ayapaP 02 stiurF 09

108

Fertilizer nutrient recommendations are listedfor N, P, K, Mg, S and organic materials inTables 3-20 and 3-21 as guidelines to achievecommonly occuring low yields and larger targetyields in tropical upland situations. Wheneverorganic materials are recommended these areseen as necessary soil amendments andadditional sources of nutrients. Application ofthese materials in most tropical uplands is aprecondition to ensure efficient utilization ofmineral fertilizer nutrients and good soil’physical’ fertility.

The nutrient content of mineral fertilizers isalways reported on the outside of bags of allquality fertilizers in terms of the amount of N,P205, K20 and MgO and this is why the fertilizerrecommendations stated here use the oxideforms for P, K and Mg (Table 3-14).

Calculating fertilizer application rates.

The following example is provided todemonstrate how to calculate amounts offertilizer materials required to deliver thenutrient recommendations provided in Table3-20 and 3-21.

Example

Crop: Hybrid maize

Grain yield target: 4.5 t ha-1 (low)

Fertilizer nutrient recommendation (kg ha-1):80 N 50 P205 60 K20 20 MgO 10 S

Fertilizer materials available (Table 3-14):

Urea (46% N),

Ammonium sulphate (AS) (21% N, 24% S),

SP36 (34% P205 )

MOP/KCl (60% K20 ), and

GML (20% MgO).

Question 1: Is there a source of S?Answer: Yes, AS (24% S)

How much AS is needed to provide 10 kg Sha-1?

24 kg S is contained in 100 kg AS

1 kg S is contained in 100 ÷ 24 = 4.16 kg AS

10 kg S is contained in 4.16 x 10 = 41.6 kg AS

42 kg of AS is required to apply 10 kg S ha-1

(42 kg of AS also contain 8.8 kg of N! Thisamount must be deducted from therecommended rate of 80 kg N ha-1).

Question 2: Is there a source of Mg?Answer: Yes, GML (20% MgO)

How much GML is needed to provide 20 kgMgO ha-1?

20 kg MgO is contained in 100 kg GML.

As GML is a slow release Mg source and onlysmall amounts (e.g. 10%) of the Mg containedusually become plant available, it is suggestedto apply 10 x 100 = 1,000 kg GML ha-1 to meetrequirements.

Question 3: Is there a source of K?Answer: Yes, MOP/KCl (60% K20)

How much MOP/KCl is needed to provide 60kg K20 ha-1?

60 kg K20 is contained in 100 kg MOP/KCl

100 kg MOP/KCl are required to apply 60 kgK20 ha-1.

Question 4: Is there a source of P?Answer: Yes, SP36 (34% P205)

How much SP36 is needed to provide 50 kgP205 ha-1?

34 kg P205 is contained in 100 kg SP36

1 kg P205 is contained in 100: 34 = 2.94 kgSP36

50 kg P205 is contained in 2.94 x 50 = 147 kgSP36

147 kg of SP36 is required to apply 50 kg P205

ha-1.

109

Question 5: Is there a source of N?Answer: There are two sources of N:Urea (46% N) and AS (21% N); 42 kgAS (as a source of S) supply already 8.8kg N ha-1.

How much urea is needed to supply theremaining (80 - 8.8) 71.2 kg N ha-1?

46 kg N is contained in 100 kg urea

1 kg N is contained in 100: 46 = 2.17 kg urea

71.2 kg N is contained in 2.17 x 71.2 = 154.8kg urea

155 kg of urea and 42 kg AS are required toapply 80 kg N ha-1

To make this recommendation practical forextension purposes the recommendation for1 ha is:

3 bags of urea (150 kg urea)

1 bag of SA (50 kg SA)

3 bags of SP36 (150 kg SP36)

2 bags of MOP/KCl (100 kg MOP/KCl)

20 bags of GML (1000 kg GML)

This will supply the recommended 80 kg N,50 kg P205, 60 kg K20, 20 kg MgO and 10 kgS.

Additional remarks

As ground magnesium limestone (GML)usually contains 40—50 % CaO the applicationof 100kg GML ha-1 will also supply calcium (Ca)and may increase soil pH slightly ( usually abeneficial effect on acid soils).

In addition, a minimum of 5 t FYM ha-1 isrecommended to improve physical soilconditions, nutrient availability and supply soilorganic matter and micronutrients to the crop.

FYM and GML are best applied before landpreparation and incorporated with the soil Pand K fertilizers.

One part (e.g., 2 bags of urea = 46 kg N ha-1)of N fertilizers is usually applied before or atplanting (as a basal dressing).

The remaining part of N-fertilizers (e. g. 1 bagof urea and 1 bag of AS providing togetheraround 33 kg N ha-1) is then applied to the crop(top dressing) at a later growth stage (e.g., 6—8 leaf stage).

110

3-8 Micronutrients

Eight of the 16 essential plant nutrients areknown as micro-nutrients, and are sometimescalled trace elements (TE) or minor elements.They include boron (B), cobalt (Co), copper(Cu), chlorine (Cl), iron (Fe), manganese (Mn),molybdenum (Mo) and Zinc (Zn). Theiravailability in soils is affected to a large degreeby soil pH (Figure 2-1).

The most abundant micro-nutrient in soils isiron (Fe) followed by Mn, Zn, Cu, Cl, B, andMo. Micronutrients, particularly the metalcations (Cu, Fe, Mn, Zn) are present asminerals, metal-organic complexes and asexchangeable cations in soils. Organic formsare of lesser importance in the case of Mo andCl. Deficiency levels of micronutrients in soilsand plants depend on the extractants andmethods of analysis used. General indicatorsare given in table 3-17 and 3-19.

Although the micronutrients presented hereare required only in very small amounts theyare essential for plant growth (some especiallyfor animals e.g., Co). Their deficiency can leadto significant yield reduction and even to totalcrop failure.

Special analytical processes of soil and plantare required to determine micro-nutrientconcentrations. Sometimes the assistance ofan expert is required or it may be necessary

to carry out some pot experiments to definedeficiencies and/or toxicities of these elementsin soils and plants.

A farmer or planter should look for specialistadvice wherever and whenever symptomssimilar to those listed in Table 3-17 and 3-19occur in otherwise healthy crops that weresupplied with sufficient N, P, K, Ca, Mg, andS. The most common fertilizer micro-nutrientsources are listed in table 3-19. There arenumerous other sources commerciallyavailable, particularly for foliar application (e.g.,as chelated products). Also, a number ofcommon NPK compounds are carriers ofmicro-nutrients (e.g., B, Zn, Cu). If appliedrepeatedly or in large amounts, somecommercially available organic nutrientsources such as slurries, urban wastes andcomposts carry large enough amounts ofmicro-nutrients to cause toxicity in plants. It isalways advisable to analyse such residues andwaste products for trace elements and toxicelements (e.g., heavy metals) beforeapplication.

There are other trace elements which havebeen found essential or useful for plants suchas chromium (Cr), nickel (Ni), iodine (I),selenium (Se) and silicon (Si) but which arecommonly not related to deficiency and onlyseldom to toxicity (e.g., large concentrationsof Cr and Ni in ultramafic soils) in plants.

Table 3-17 Micronutrients concentration in soils, and pH ranges for maximum availability.

tneirtunorciM lobmyS gkgmtnetnoclatoT 1- egnarHpmumitpO

noroB B 036–01 0.7–0.5

tlaboC oC 04–1 5.5–0.5

reppoC uC 069–1 5.6–0.5

enirolhC lC 008–5 detceffaton

norI eF 000,001–000,3 0.6–0.4

esenagnaM nM 000,5–03 5.6–0.5

munedbyloM oM 81–1.0 5.8–0.6

cniZ nZ 006,1–2 5.6–0.5

111

Table 3-18 Factors contributing to micronutrient toxicities, toxicity symptoms and toxicitylevels in plants

srotcafyticixoT smotpmysyticixoTslevelyticixoT

gkgm 1-

BfosnoitacilppaegraL

tsopmocnabrufaelfosisorcendnasisorolhC

snigramfaeldnaspit002>

oC

ylhgih,ydnas(slioS)ytaep,suoeraclac

sedixonM/lA/eFeganiard,gnimiL

raelcnullits(nwonktoNtceridasahoCrehtehw

)stnalpninoitcnuf

emos(0001>)0004>seiceps

uC

sliosfonoitanimatnoCsnoitacilppaegraloteud

nabrudnaseirrulsfotsopmoc

redlofosisorcendnasisorolhCsevael

noitagnoletoorfonoitibihnI02>

lC

latsaocdeniardylrooPdetceffa-tlasdnaslios

foecnarelottlas,saeraseiceps

htworgdnagnihcrocsfaeL-tlasniyllaicepse(noitibihni

)sravitlucevitisnes0053>

eF,sliosdegrembuSsaeradeggolretaw

elprupdna,ecirnigniznorBrehtonisevaelfonoitarolocsid

sporc005>

nM,sliosdegrembuSsaeradeggolretaw

snievfaelnostopsnworBdnaspitfaeltagnitratssisorcen

gnilknircfael,snigram005>

oMoMotnoitiddanignimiL

noitacilppa

wolley-egnarootnedloG)elprupsemitemos(

noitarolocsidsedonretnitrohS

0001>

nZneercsdnassalgrednU

sfooresuoh

sruccoyleraRfoesohtotralimissmotpmyS

ycneicifednMdnaeF004>

112Table 3-19 Factors contributing to micronutrient deficiencies, deficiency symptoms and deficiency levels in plants

srotcafycneicifeD smotpmysycneicifeDycneicifeDgkgmlevel 1-

tneirtunorcimnommoCsecruos

B,ydnas,laivulla(slioS

,rehtaewyrd;Hphgih;)cinagroytisnetnithgilhgih

dnasevaeltsegnuoyfonoitrotsiDsdub

51< )B%51(etarobartetmuidoS

oC,suoeraclacylhgih,ydnas(slioS

;sedixonM/lA/eF;)ytaepeganiard,gnimiL

dnadecudersinoitcefnimuibozihRN2 semugelnideyalednoitaxif

1.0< etahplus-oC

uClioshgih;)cinagro,ydnas(slioS

;nZ,Planiev-retni,gnitliwsevaelgnuoY

gniwolley4< )uC%52(etahplus-uC

lCmorfyawasetiS;)ydnas(slioS

sporcevitisneS;aeseht)mlaplio,tunococ(

,sevaelregnuoyfosisorolhCgnitliwllarevo

005< )lC%84(lCK/POM

eF,rettamcinagrowol(sliosdicA

OCaCeerF;)noitarearoop 3

fo)etihw-wolley(sisorolhCneewtebsaeranisevaeltsegnuoy

seniev05< )eF%91(etahplus-eF

nM

deniardylroopdnaenilaklA;nZ,uC,eFliosnihgih,slios

,ytisnetnithgilwol,rehtaewyrderutarepmetlioswol

htiwnetfo(sisorolhctopsdnapirtSdaerpshcihwsnoiselnworb-yerg

regnuoynognitrats)emithtiwsevael

02< )nM%03(etahplus-nM

oM eFeerf;snoitidnocdicA

,snigramdnaspitfaelcitorceNsemitemosgnilknirc,gnillor

regnuoyyltsomfonoitarofrepsevael

1.0<etadbylom-muinommA

)oM%45(

nZ;Plioshgih;sliossuoeraclaC

sliosdetcapmoc

gniworgtsaf)etihwnetfo(citorolhCgnuoyllams,senievneewtebstops

)eziamfo'dubetihw'(sevael02< )nZ%12(etahplus-nZ

113

Table 3-20 Balanced N, P, K, and Mg-fertilizer nutrient recommendations for 45 crops.

porC tcudorP dleiY N P2O5 K2O OgM

woL hgiH woL hgiH woL hgiH woL hgiH woL hgiH

aht 1- ahgk 1-

slaereC

dirbyheziaM niarG 5.4 5.4 08 051 05 061 06 051 02 04

lacoleziaM niarG 5.2 5.2 05 001 02 08 02 06 5 01

devorpmieciR niarG 4 4 08 061 02 08 03 09 01 02

lacoleciR niarG 2 2 08 511 02 04 02 03 5 01

sporctooR

avassaC stooR 21 02 04 002 02 08 02 001 5 02

oraT srebuT 01 02 0 05 02 06 0 06 01 02

otatoP srebuT 01 51 04 001 02 08 02 001 01 04

otatoPteewS srebuT 8 51 7 001 02 08 03 06 01 05

maY srebuT 51 52 0 08 02 08 02 08 5 02

semugeldooF

snaeB snaeB 2 3 02 04 02 06 03 06 51 03

aepwoC niarG 1 1 01 02 03 04 02 03 01 03

tundnuorG niarG 2 3 01 05 02 08 0 06 01 03

snaebgnuM niarG 5.0 1 01 02 03 04 02 03 51 03

naebyoS niarG 1 2 0 06 03 06 0 06 01 03

selbategeV

torraC stooR 01 02 02 06 02 06 03 001 5 02

rebmucuC tiurF 01 02 08 051 02 08 09 002 01 02

tnalpggE tiurF 01 02 05 002 06 051 08 002 01 02

naebgnoL snaeB 8 51 02 04 02 06 03 06 01 02

arkO tiurF 8 51 06 021 06 001 06 021 5 02

noinO sbluB 02 03 06 051 08 021 09 051 5 02

reppepteewS tiurF 01 02 09 051 08 051 09 052 01 03

nrocteewS sboC 01 02 09 021 08 021 08 021 5 01

otamoT tiurF 01 02 08 021 08 051 09 002 01 02

114

Table 3-20 ...continued (last).

porC tcudorP dleiY N P2O5 K2O OgM

woL hgiH woL hgiH woL hgiH woL hgiH woL hgiH

aht 1- ahgk 1-

sporctiurF

odacovA tiurF 01 01 001 002 002 003 002 003 5 01

ananaB tiurF 02 03 001 003 001 003 002 004 06 051

nairuD tiurF 6 21 001 051 05 051 001 002 02 04

ognaM tiurF 6 51 08 051 05 051 05 051 02 04

egnarO tiurF 01 02 001 051 05 051 001 002 02 04

ayapaP tiurF 01 02 08 002 001 002 001 003 5 01

elppaeniP tiurF 03 06 002 003 05 051 002 003 03 05

natubmaR tiurF 5 51 05 051 05 051 05 051 5 02

nolemretaW tiurF 01 02 05 001 06 021 08 002 02 04

sporceerT

aocoC snaeB 1 2 04 06 05 07 05 07 04 06

sevolC sevolC 3.0 1 05 001 03 09 001 002 01 02

tunocoC stuN 6 01 05 001 03 06 08 001 01 03

eeffoC snaeB 1 2 001 002 05 002 051 003 01 03

mlapliO hcnuB 02 03 08 051 05 051 001 003 02 06

rebbuR xetaL 5.0 5.1 01 03 02 03 05 001 5 01

aeT aeT 5.0 5.1 001 051 03 08 03 08 01 03

sporchsaC

enacraguS enaC 06 001 08 021 06 021 001 002 01 03

occaboT sevaeL 1 2 02 05 04 001 05 051 01 02

secipS

seillihC sdoP 2 3 08 021 06 021 08 051 04 08

reppeP snroc/P 1 3 001 004 001 002 001 005 04 08

sporcreddoF

ssarG MD 4 8 05 002 03 09 04 08 02 03

semugeL MD 5 01 05 002 03 09 04 08 02 03

115Table 3-21 List of Latin, English and Indonesian names for crop plants.

porC tcudorP

dleiY S lairetamcinagrOstnemmoC

woL hgiH woL hgiHlairetaM

woL hgiH

aht 1- ahgk 1- aht 1-

slaereC

dirbyheziaM niarG 5.4 5.4 01 02 MYF 5 01 norobddA

lacoleziaM niarG 5.2 5.2 5 01 MYF 5 01 –

devorpmieciR niarG 4 4 01 02 wartS 5 5 cnizddA

lacoleciR niarG 2 2 5 01 wartS 5 5 –

sporctooR

avassaC rebuT 21 02 5 02 MYF –

oraT rebuT 01 02 01 02 MYF 01 01 –

otatoP rebuT 01 51 5 02 MYF 01 01 –

otatopteewS rebuT 8 51 5 02 MYF 5 5 –

maY rebuT 51 52 5 02 MYF 01 02 hclumesU

semugeldooF

snaeB snaeB 2 3 51 02 MYF 5 5 emilsdeeN

aepwoC niarG 1 1 01 02 MYF 5 5 noitarutaslAfotnareloT

tundnuorG niarG 2 3 01 02 MYF 5 5ahemilgk003ddA 1- worotnoitamroftunaeprof

naebgnuM niarG 5.0 1 01 02 MYF 5 5 emilsdeeN

naebyoS niarG 1 2 01 02 MYF 5 5 emilsdeeN

116Table 3-21 ...continued.

porC tcudorP

dleiY S lairetamcinagrOstnemmoC

woL hgiH woL hgiHlairetaM

woL hgiH

aht 1- ahgk 1- aht 1-

selbategeVtorraC stooR 01 02 5 02 MYF 01 02 rezilitrefetaroprocnI

rebmucuC tiurF 01 02 5 02 MYF 01 02 –

tnalpggE tiurF 01 02 5 01 MYF 01 01 –

naebgnoL snaeB 8 51 5 01 MYF 01 01 –

arkO tiurF 8 51 5 01 MYF 01 01 –

noinO sbluB 02 03 5 02 MYF 01 01 emilsdeeN

reppepteewS tiurF 01 02 01 02 MYF 01 01 etimolodylppA

nrocteewS sboC 01 02 01 02 MYF 01 01 –

otamoT tiurF 01 02 01 02 MYF 01 01 –

sporctiurFodacovA tiurF 01 01 01 02 MYF 5 5 –

ananaB tiurF 02 03 02 06 MYF 01 03 5.5HpotemiL

nairuD tiurF 6 21 02 03 MYF 5 5 –

ognaM tiurF 6 51 0 01 MYF 5 5 –

egnarO tiurF 01 02 01 02 MYF 5 5 –

ayapaP tiurF 01 02 5 01 MYF 5 01 norobesU

elppaeniP tiurF 03 06 01 02 MYF 5 01 nootarotrezilitref%05

natubmaR tiurF 5 51 5 01 MYF 5 01 –

nolemretaW tiurF 01 02 5 01 MYF 01 01 hclumesU

117Table 3-21 ...continued (last).

porC tcudorP

dleiY S lairetamcinagrOstnemmoC

woL hgiH woL hgiHlairetaM

woL hgiH

aht 1- ahgk 1- aht 1-

sporceerT

aocoC snaeB 1 2 02 03 enoN norobesU

sevolC sevolC 3.0 1 5 01 MYF 5 01 hclumesU

tunocoC stuN 6 01 5 01 enoN –

eeffoC snaeB 1 2 01 02 MYF 5 01 –

mlapliO hcnuB 02 03 5 01 enoN norobesU

rebbuR xetaL 5.0 5.1 0 5 enoN –

aeT aeT 5.0 5.1 5 01 enoN hclumesU

sporchsaC

enacraguS enaC 06 001 5 01 ekac/F 01 01 nootarotrezilitref%05

occaboT sevaeL 1 2 01 02 MYF 01 01 emilsdeeN

secipS

seillihC sdoP 2 3 01 02 MYF 01 01 –

reppeP snroc/P 1 3 02 04 MYF 01 01 emilsdeeN

sporcreddoF

ssarG MD 4 8 5 01 enoN –

semugeL MD 5 01 5 01 enoN,.g.e,seicepstnarelot-lAesU

ainroZ ,.pps muidomseD .pps

118

3-9 Timing of FertilizerApplication

Nitrogen

N uptake by plants is favored under low pHconditions and the udic moisture regime inmost of the acid soils in Southeast Asia butleaching losses of freely moving nitrate (NO3-N) can be severe if crops are not growingvigorously enough or if the land is not protectedby a plant cover. Ammonia nitrogen application(e.g., as urea) before planting is even morelikely to be lost by leaching followingnitrification or to the atmosphere byvolatilization. In addition N losses bydenitrification may be enhanced during therainy season due to periodic water-logging.

To avoid such losses, time N application asclose as possible to the peak requirement of aseasonal crop or, in perennial cropping

systems, distribute the required annual amountaccording to weather conditions and the cropdevelopment stage.

Phosphorus

Soluble P forms (e.g., TSP) are transformedinto less available forms when applied to acidsoils. Therefore, P fertilizer should not beapplied in advance of seeding (for tree-cropsplace P fertilizer in the planting hole). Place Pfertilizer in bands near the seed or transplantedseedlings (sometimes also place P fertilizer indeep bands before planting) in low P statussoils and P fixing soils. Large initial rates ofless soluble P sources (e.g., 1 t RP ha-1) onacid soils poor in P should be broadcast andincorporated in the top soil (e.g., together withFYM) during land preparation.

Table 3-22 Timing of fertilizer appliucation in relation to soil properties, climate and croprequirements

lioS etamilC sporC

N

ON(etartiN 3-)

Hpwolnignihcael-llewderutxetthgil

.sliosdeniardHN(ainommA 3)

regralnoitazilitalov.Hpgnisaercnihtiw

gnihcaeldesaercnIfosdoirepgnirud

.llafniarhgihdesaercnI

gnirudnoitacifirtinhgihfosdoirep

.erutarepmet

sporclaunnA ylppusdesaercnI:gnirewolf,egatsgnuoytadedeen

.segatskaepgniruddnasporclainnereP enilniylppuS:

.elcycporcdnarehtaewhtiw

P

noitprosgnortSenifni)noitaxif(

-lA/nM/eFderutxetgniniatnoc-edixo

.sliosdica

fosessoldesaercnIPdeilppaecafrus

dnaffonurybhgihgnirudnoisore

dnastnevellafniar.sdoirep

sporclaunnA taroerofeB:ecafrushtiwdetaroprocnignitnalp

.liosraensporclainnereP dnalgniruD:

htiwdetaroprocninoitaraperpehtotdna/roliosraenecafrus

.elohgnitnalp

K

dnaderutxetthgiLsliosdeniardllewyamMOSniroop

.gnihcaelenorpebnislarenimcitillI(

slioslaciportemosnoitaxifesuacyam

)Kfo

laitnetopdesaercnIffo-nur,gnihcael

gnirudnoisoredna.sdoirepllafniarhgih

sporcdeilppuslleWyrddnatshtiwnac

.rettebsdoirep

sporclaunnA taroerofeB:ecafrushtiwdetaroprocnignitnalp

.e(setarnoitacilppaegraL.liosraenKgk021>.g 2 ahO 1- tilpsebdluohs)

pot2ro1+lasab%05,.g.e(.)sgnisserd

sporclainnereP niylppusralugeR:.selcycporcdnarehtaewhtiwenil

119

Potassium

Potassium is commonly applied before or atplanting for annual crops. Perennial cropsshould be supplied with K regularly before theonset of the wet season and in line with cropgrowth.

K is a cation and its interaction with othercations (e.g., Ca and Mg) in relation to the soil’scation exchange capacity will reduce itsmovement. However, K from soluble sources(e.g., MOP/KCl) may be leached in lighttextured, well drained soils containing a smallamount of soil organic matter, particularly if theK fertilizer is applied in large amounts at onetime. Split application (e.g., one half of therecommended rate at planting and the otherhalf in 1—2 splits at later growth stages) canreduce leaching losses if rates of >120 kg K2Oha-1 are recommended.

Calcium, Magnesium, and Sulfur

As these nutrients are usually required insmaller amounts and are often contained inorganic nutrient sources (e.g., FYM) and soilamendments (e.g., Ca in lime, Ca and Mg inGML) and fertilizer NPK nutrient sources (e.g.,S in AS, Ca and S in SSP, Ca in TSP) theymay be sufficiently supplied if these sourcesare used. If additional amounts are required,Mg and S should be applied at or beforeplanting (e.g., as kieserite or langbeinite) toannual crops and annually to perennials.

Micronutrients

As micronutrients are only required in smallamounts supply from organic sources (e.g.,FYM) can be sufficient for average yields.Specific crop requirements should beaddressed before or at planting (e.g., Zn) andfor some crops at times when demand is great(e.g., B before periods of vigorous growth)using special nutrient sources (e.g., compoundfertilizers containing crop specific micronutrientadditions) and special applications (e. g. asfoliar sprays).The problem of time of fertilizerapplication becomes generally less important,as higher rates of fertilizer are used and soilfertility increases.

In rotations, soybeans and other ’secondarycrops’ (palawija crops) are traditionally seenas nutrient scavengers. If high yieldingvarieties are grown, however, (e. g. hybridmaize), the larger amounts of nutrientsremoved in grain yield must be allowed for andsucceeding crops in the rotation should besupplied separately. Also, where irrigation isused the supply of fertilizer nutrients shouldbe increased in order to make more efficientnd economic use of added water.

120

3-10 Fertilizer storage andcompatibility

Improperly stored or mixed fertilizer storagecan result in large losses of nutrients. Hereare some important aspects to consider infertilizer mixing and storage:

� Urea should not be mixed with AN.

� Urea can be mixed with most fertilizer butjust before application. Do not store suchmixtures.

� Ammonium phosphates and superphosphates should not be mixed withlime, slag, or rock phosphate.

� MOP and SOP can be mixed with mostfertilizers but their mixtures with urea andCAN cannot be stored.

� CAN should not be mixed with basic slagbut can be mixed with urea, SSP, andammonium phosphates just beforeapplication.

� Keep fertilizer bags away from damp anddirty places and stored where roofs arenot leaking and wall and floors don tcatch dampness.

� Critical relative humidity (CRH) values ata standard temperature of 30°C areshown in table 3-23. Above the CRH

value the fertilizer will start to absorbwater. Fertilizers tend to absorb waterfrom the atmosphere (they arehygroscopic). When fertilizers absorb toomuch water from the atmosphere, theybecome caked and almost cement-like,rendering them practically unusable.Fertilizers that have a low CRH willabsorb atmospheric moisture first (e.g.,urea with a CRH of 70 will begin to clumptogether sooner than ZA, which has aCRH of 79).

Table 3-23 Critical relative humidity vluesfor selected fertilizers.

rezilitreF HRC

etartinmuinommA 85

aerU 07

edirolhcmuissatoP 67

etahplusmuinommA 97

etahpsohprepuselpirT 59

hsatoPfoetahpluS 69

ytidimuhevitalerlacitirc=HRC

121

Table 3-24 Acidification and salt index values for commonly used fertilizers

lairetaMgkytidicA

OCaC 3 g001 1-

lairetam

xednitlaSgkgk( 1-

)lairetam

aerU 48- 4.57

etartinmuinommA 36- 7.401

etahplusmuinommA 211- 96

etahpsohpmuinommaonoM 56- 9.92

etahpsohpmuinommaiD P%45 2O5 47- 2.43

P64 2O5 46-

etahpsohprepuS P%84 2O5 1.01

P%54 2O5 1.01

P%02 2O5 0 8.7

?etahpsohpdeniclaconoM 0

?etahpsohpdeniclaciD 73+

?etahpsohpdeniclacirT 46+

58-

etartinmuidoS 92+ 001

etartinmuissatoP 62+ 6.37

etartinmuiclaC 02+

N%9.11 1.16

etahpsohpkcoR 65+

edirolhcmuissatoP 0 3.611

etahplusmuissatoP K%45 2O 0 1.64

)deniclac(etahplusmuisengaM OgM%4.33 0 7.83

muspyG 0 1.8

eticlaC 59–08+ 7.4

etimoloD 001–09+ 8.0

122Table 3-25 Legume crops, shrubs and trees in upland agriculture.

esU sporCNfo%dexif

stnemmoC

niarGsemugel

aeagopyhsihcarAnajacsunajaC

xamenicylG.ppssuloesahP

.ppsangiV

29–7488

78–0727–5189–23

.porcelgnisasaniargstirofnworgsiporC.srexifroopnetfoera.pssuloesahP

.niargehtnidevomersiNfotnuomaegralA.noitaluconiotsdnopseryllausunaebyoS

.noitaluconiotsdnopseryleraraepwoC

erutsaPtnemevorpmi

.ppsamesortneC.ppsmuinogopalaC

.ppsmuidomseDsedioloesahpairareuP

.ppssehtnasolytS.ppsainroZ

38–28–0788

29–1788

.erutsapgnitsixenaotniemugelehttnalPadnassargdevorpmifoerutximahtiwnoitategevgnitsixeehtecalpeR

.emugel.)knabnietorparo(erutluconomemugelahsilbatsE

.stnanimurkcotsevilrofreddofhcir-nietorpedivorP.sessargerutsapybpunekatNfotnuomaesaercninaC

.erunamlaminarorettiltnalpniliosehtotdenrutersiNdexifehtfotsoM

yrotsrednUnisemugel

noitatnalpsporc

muinogopolaCsedionucum

snecsebupamesortneCsedioloesahpairareuP

nopracoretehmuidomseD)muilofilavo(

08–06 .mlapliodnarebburnidesunetfostnalprevoCNcirehpsomtaxifnacyehtesuacebslioselitrefninitsafworG 2.

.smelborptoorlagnufdnadeew,noisoreliosecudeR.rebburnipeehs,tunococnielttacgnizarghtiwdetargetniebnaC

niseertedahSnoitatnalp

sporc

susryhtolacardnaillaCmuipesaidicirilG

anaigippoepanirhtyrE

ottluciffiDerusaem

.eniniuqdna,aet,eeffoc,aococrofdesussertedahS-N.rezilitreffostnuomallamsesutahtsgnidlohllamsrofdoogeerT

.tifenebedisasinoitaxif.rebmitfoecruosaeraseerT

123Table 3-25 ... continued (last).

esU sporCNfo%dexif

stnemmoC

elpitluMporc(gnipporc

)snoitator

aeagopyhsihcarAxamenicylG

najacsunajaCataidarangiV

? !NdexifniedivorpyehtnahtNlioseromevomeryamsporC

elpitluMgnipporc

neerg(dnaserunam)stnalprevoc

najacsunajaCaecnujairalatorC

.ppsbalbaL.ppsanucuM

.ppsainabseSataidarangiV

etalumuccANgk052–32

ah 1-

NdnalairetamcinagrorofylnonworG 2 tonsiN.porctxenehtrofnoitaxif.stcudorpporcnidevomer

nahtNfonoitazilarenimdipareromnistluserhserfliosotnidehguolP.seudiseremugelniargmorf

dnatsep,deewrofoslatub,tnemevorpmiytilitrefliosrofdesuyllausU.lortnocnoisore

elpitluMgnipporc

)gnipporcretni(

.ppssuloesahPaeagopyhsihcarA

? tahteziamsahcus,porclaerecahtiwdepporcretniebnacsuloesahP.troppuslacisyhpsedivorp

fotsomsedivorpemugelehtesuacebemugelnonehtrofderapsNlioSNmorfstnemeriuqerNsti 2 .noitaxif

yrtseroforgAdnadoowleuf(

)rebmit

muignamaicacAairataclafsehtnairesaraP

66–2555

sporclaunnahtiwdepporcretniebnacseert,doowpluprofnworgnehW.sraey3–2rof

yrtseroforgAdnadoof(

)egarof

muipesaidicirilGsusryhtolacardnaillaC

arolfidnargainabseS

57–6241–068–87

.teidssargkcotseviltnemelppusotnietorpfosecruostnatropmIsaro,serutsapnignisworbtceridrofseertsadetaroprocniebnaC

rofsknabreddofsadna,spirtsruotnocgnola,senilecnef,sworegdeh.smetsysyrracdnatuc

124

Table 3-26 List of Latin, English and Indonesian names for crop plants.

nitaL hsilgnE naisenodnI

muignamaicacA muignaM muignaM

.ppsaicacA aicacA aisakA

apecmuillA noinO gnawaB

susonocsanonnA elppaeniP saneN

aeagopyhsihcarA tundnuorG hanatgnacaK

snebmucedairahcarB ssarglangiS langistupmuR

najacsunajaC aepnoegiP eduggnacaK

sedionucummuinogapalaC opalaC muinogopolaK

susryhtolacardnaillaC ardnaillaC rednailaK

sisnenisaillemaC aeT heT

.ppsmucispaC reppepilihC ebaC

.ppsmucispaC reppepteewS akirpaP

ayapapaciraC ayapaP ayapeP

snecsebupamesortneC ortneC ortneS

atarodoanealomorhC deewmaiS uynireK

satanalsullurtiC nolemretaW akgnameS

.ppssurtiC egnarO kureJ

.ppssurtiC surtiC kureJ

areficunsocoC tunocoC apaleK

.ppsaeffoC eeffoC ipoK

atnelucseaisacoloC mayocoC salat/oraT

aecnujairalotorC pmehnnuS )avaJ(tubmelkoro-korO

suvitassimucuC rebmucuC numiT

atoracsucuaD torraC letroW

.ppsmuidomseD muidomseD koteb,kisiS

siraenilsiretponarciD nrefnekcarblaciporT maseR

.ppsaerocsoiD maY gnudnag,apalekibU

sunihtebizoiruD nairuD nairuD

sisneeniugsiealE mlapliO tiwasapaleK

anaigippoepanirhtyrE anirhtyrE padaD

125

Table 3-26 ...continued.

nitaL hsilgnE naisenodnI

acitamoraaineguE sevolC hekgneC

allyhporcamaignimelF aignimelF aignimelF

muipesaidicirilG aidicirilG lamaG

xamenicylG naebyoS eledeK

sisneilisarbaeveH rebbuR teraK

sutnelucsesucsibiH regnifs'ydaL/arkO arkO

acirdnilycatarepmI atarepmI,ssargraepS gnala-gnalA

satatabaemopI otatopteewS ralajibU

sueruprupbalbaL naebhtnicayh,balbaL kamoK

alahpecocuelaneacueL aneacueL orotmaL

mutnelucsenocisrepocyL otamoT tamoT

acidniarefignaM ognaM aggnaM

atnelucsetohinaM avassaC uyakibU

.psacuelaleM acuelaleM hitupuyak,maleG

mucirhtablamamotsaleM nordnedodohrstiartS kududneS

.psnolyxorteM mlapogaS ogaS

.ppsanucuM anucuM kukgnebaraK

.ppsasuM ananaB gnasiP

muecappalmuilehpeN natubmaR natubmaR

mucabatanaitociN occaboT uakabmeT

avitasazyrO eciR idaP

munacirema.Pxmueruprup.P ssarggniK ajartupmuR

airataclafsehtnairesaraP sehtnairesaraP nogneS

mueruprupmutesinneP ssargtnahpelE hajagtupmuR

anaciremaaesreP odacovA takopA

.ppssuloesahP naebnommoC sicnuB

murginrepiP reppeP adaL

sedioloesahpairareuP uzduklaciporT gnadnark,airareuP

.ppsmurahccaS enacraguS ubeT

arolfidnargainabseS ainabseS iruD

126

Table 3-26 ...continued (last).

nitaL hsilgnE naisenodnI

acilatiairateS airateS )avaJnotuwawaJ(ynam

anegnolemmunaloS tnalpggE gnureT

musorebutmunaloS otatoP gnatneK

sisnenaiugsehtnasolytS olytS –

oacacamorboehT aocoC oakaK

sedioinazizareviteV ssargreviteV revitevtupmuR

ataidarangiV naebgnuM uajihgnacaK

ataluciugnuangiV naebgnoL gnajnapgnacaK

ataluciugnuangiV aepwoC kaggnutgnacaK

syamaeZ eziaM gnugaJ

elanicifforebigniZ regniG ehaJ

Table 3-27 Symbols and atomic weights for elements involved in plant nutrition

emaN lobmyS .twcimotA emaN lobmyS .twcimotA

muinimulA lA 97.62 esenagnaM nM 39.45

noroB B 28.01 munedbyloM oM 59.59

muiclaC aC 80.04 negortiN N 10.41

enirolhC lC 64.53 lekciN iN 96.85

tlaboC oC 49.85 negyxO O 00.61

reppoC uC 75.36 surohpsohP P 98.03

eniroulF F 00.91 muissatoP K 01.93

negordyH H 10.1 muidoS aN 00.32

enidoI I 29.621 ruhpluS S 60.23

norI eF 58.55 cniZ nZ 83.56

muisengaM gM 39.45 nociliS iS 60.82

nobraC C 10.21 muineleS eS 69.87

127

Table 3-28 Nutrient convertsion factors

morFylpitlum

ybmorf/tegot

ylpitlumyb

tegot

ON 3 622.0 N 724.4 ON 3

HN 3 028.0 N 612.1 HN 3

HN 4 677.0 N 882.1 HN 4

HN(OC 2)2 aeru- 364.0 N 061.2 HN(OC 2)2 aeru–

HN( 4)2 OS 4 212.0 N 617.4 HN( 4)2 OS 4

HN 4 ON 3 053.0 N 758.2 HN 4 ON 3

P2O5 634.0 P 192.2 P2O5

aC 3 OP( 4)2 854.0 P2O5 281.2 aC 3 OP( 4)2

K2O 038.0 K 502.1 K2O

lCK 236.0 K2O 085.1 lCK

lCK 525.0 K 509.1 lCK

OSnZ 4. H2O 063.0 nZ 877.2 OSnZ 4

. H2O

OSnZ 4. H7 2O 032.0 nZ 843.4 OSnZ 4

. H7 2O

OS 2 105.0 S 799.1 OS 2

OS 4 433.0 S 699.2 OS 4

OSgM 4 762.0 S 057.3 OSgM 4

4OSgM . H2O 032.0 S 013.4 OSgM 4. H2O

OSgM 4. H7 2O 031.0 S 086.7 OSgM 4

. H7 2O

HN( 4)2 OS 4 052.0 S 599.3 HN( 4)2 OS 4

OiS 2 iS OiS 2

OiSaC 3 iS OiSaC 3

OiSgM 3 iS OiSgM 3

OgM 306.0 gM 856.1 OgM

OgM 689.2 OSgM 4 533.0 OgM

OgM 234.3 OSgM 4. H2O 092.0 OgM

OgM 052.6 OSgM 4. H7 2O 061.0 OgM

OgM 190.2 OCgM 3 874.0 OgM

128

Table 3-28 ...continued.

morFylpitlum

ybmorf/tegot

ylpitlumyb

tegot

OaC 517.0 aC 993.1 OaC

OCaC 3 065.0 OaC 087.1 OCaC 3

OaC 517.0 aC 993.1 OaC

lCaC 2 aC lCaC 2

OSaC 4 aC OSaC 4

aC 3 OP( 4)2 aC aC 3 OP( 4)2

OSeF 4 863.0 eF 027.2 OSeF 4

OSnM 4 463.0 nM 847.2 OSnM 4

lCnM nM lCnM

OCnM 3 nM OCnM 3

OnM 2 nM OnM 2

OSuC 4. H2O uC OSuC 4

. H2O

OSuC 4. H5 2O uC OSuC 4

. H5 2O

aN 2B4 7O . H5 2O B aN 2B4 7O . H5 2O

aN 2B4 7O . H7 2O B aN 2B4 7O . H7 2O

129

Table 3-39 Weights and measures.

htgneLmm4.52=mc45.2=toof380.0ro21/1=hcnI

mc84.03=m8403.0=sehcni21=tooFm4419.0=teef3=sehcni63=draYm30.5=sdray5.5=teef5.61=doR

sniahc08=sgnolruf8=mk16.1=teef082,5=sdray067,1=eliM

aerAmc54.6=tooferauqs700.0=hcnierauqS 2

mc30.929=sehcnierauqs441=tooferauqS 2

m638.0=teeferauqs9=drayerauqS 2

sdorerauqs061=teeferauqs065,34=sdrayerauqs048,4=ercAm16.36= 2 ah504.0=

m000,01=eratceH 2 serca74.2=mk95.2=serca046=elimerauqS 2 noitces1=

serusaemdiuqiLlm39.4=spord08=ecnuodiulf7661.0=noopsaeTlm8.41=ecnuodiulf5.0=snoopsaet3=noopselbaT

lm85.92=snoopselbat2=ecnuodiulFmc3.572=snoopselbat61=secnuodiulf8=puC 3

lm2.374=secnuodiulf61=spuc2=tniPL587.3=secnuodiulf23=stnip2=spuc4=trauQ

strauq750.1=lm0001=stnip311.2=ertiLL587.3=stnip8=strauq4=nollaG

3.82=sdnuop4.26=snollag5.7=retawfotoofcibuC Lteefcibuc036,3=snollag451,72=retawfohcniercA

L000,001=sretemcibuc001=retawforetemitneceratceH

serusaemyrD53.0=)level(noopsaeT mc47.5=hcnicibuc 3

mc12.71=snoopsaetlevel3=hcnicibuc50.1=)level(noopselbaT 3

mc3.572=sehcnicibuc8.61=snoopsaetlevel61=puC 3

mc3.572=sehcnicibuc2.76=snoopselbat46=stnip2=trauQ 3

L8.8=sehcnicibuc835=stnip61=strauq8=kcePL53=strauq23=sehcnicibuc051.2=skcep4=lehsuB

semuloVmc4.61=toofcibuc85000.0=hcnicibuC 3

m820.0=draycibuc730.0=sehcnicibuc827,1=toofcibuC 3

m567.0=teefcibuc72=draycibuC 3

sthgieWgm000,1=sniarg34.51=marGsniarg5.734=g53.82=ecnuO

g454=sniarg000,7=secnuo61=dnuoPsdnuop502.2=g000,1=margoliK

)t(ennotcirtem610.1=sdnuop042,2=)gnol(noT

130

stinunaisenodnIecirretil1 gk8.0=

tm9600.0=sretil85.8=ecirgnatnag1gnatnag96.541=ecirtm1

ah217.0=wuob-eohab1gk57.16=lukip1gk001=latniuq1

g001=nuo1)aisenodnI(snoisrevnocporC

)gnirekhabag(ecirhguoryrdt567.0ottnelaviuqesi)idap(ecirhguorklatsyrdt1ecirdellimt86.0ottnelaviuqesi)ecirhguoryrd(gnirekhabagt1

ecirdellimt25.0ottnelaviuqesi)idap(ecirhguorklatsyrdt1slenrektundnuorgt7.0ottnelaviuqesisdoptundnuorgt1

arpoct1ottnelaviuqesistunococ5776ekact4.0dnaliotunococt6.0ottnelaviuqesiarpoct1

slluht9.0dnalaemt37.0dnaliot81.0ottnelaviuqesisnaebyosdehsurct1)yrotcafenac(ragust1.0ottnelaviuqesienacragust1

Table 3-30 Weights, measures , and conversion facrtors used in Indonesia.

131Table 3-31. Glossary of terms used in this handbook

mreT noitinifeD

retawelbaliavAyticapacgnidloh

.sporcybdesuebnactahtretawniaterotliosafoytilibaehtfoerusaemasisihT

NlacigoloiB 2 noitaxifNcirehpsomtafonoisrevnocehT 2 ehtnomroftahtseludonnievilyllausuhcihw,)aibozihr(airetcabyb

fostoor ynam .stnalpybdesuebnactahtsmrofotni,stnalpemugel

oitarN/CN/C(oitarnegortinotnobracediwahtiwslairetaM.sesopmocedlairetamtnalpaylisaewohfoerusaemAtundnuorg,.g.e(,oitarN/Cworranahtiwesohtnahtylwolseromesopmoced,)wartsecir,.g.e(hcus)oitar

.)sevael

egnahcxenoitaC)CEC(yticapac

.K,gM,aCsahcus,snoitac'otnodloh'roniaterotliosafoytilibaehT

noitarutaslAlacitirC .tnalpporcralucitrapaotcixoteratahtlAfoslevelotsdnopserrochcihwnoitarutaslAfolevelehT

noitacifirtineDON(etartinfonoitcuderlacimehcoibehT 3 ON(etirtinro) 2

- N(mrofsagaot) 2 ehtottsolebnachcihw,).erehpsomta

eganiarDehtsisihTreyalliospotehtderetnesahtahtretawssecxeffoniardotelbasiliosahcihwybesaeehT

.eliforpehthguorhtretawniarfoesopsidotliosafoytiliba

noitartlifnI .liosaotniretawfoyrtneehT

gnihcaeL .liosanistneirtunfo,retawgnitalocrepyb,tnemevomdrawnwodehT

noitazilareniMlaiborcimfotluserasamrofcinagroninaotnimrofcinagronamorftnemelenafonoisrevnocehT

noitisopmoced

ignuflazihrrocyM .surohpsohpyllaicepse,ekatputneirtunesaercniplehyamdnastoortnalptcefnitahtignuflioscipocsorciM

noitacifirtiNcinagrofoyacedehtdnanoitercxelaminamorfdeviredliosehtniainommadnasetirtinfonoisrevnocehT

.setartinotnirettam

lairetamcinagrOsa(egawesdna,serunamlamina,serunamneerg,sehclum,seudiserporc,rettildnuorg-wolebdna-evobA

.)MOSotderapmoc

132Table 3-31 ...continued (last).

mreT noitinifeD

noitaxif-PelbaliavasiPdeddaehtfoelttilyrevtahtossrezilitrefnideilppaP'pukcol'otsliosemosfoytreporpehT

.noitcarfyalcegralahtiwsliosdnaslioscinaclov'gnuoy'nisruccO.ekatputnalprof

noitalocreP .liosahguorhtretawfotnemevomdrawnwodehT

fo(tceffelaudiseR)srezilitref

stceffelaudisertrohS.deilppaerayehtretfaemitfodoireparofseitreporpliosnosrezilitreffotceffeehT,.g.e(sraeylarevestsalnacstceffelaudisergnol,)erunamneerg,.g.e(nosaesgnipporcanahtsseltsal

.)etahpsohpkcorroemil

aibozihR NcirehpsomtaxiftahtairetcablioS 2 .stnalphtiwnoitaicossani

ffonuRdnaliosyrracnacretawsihT.liosehtotnignitartlifnifodaetsniecafrusdleifehtffosnurtahtretaW

.dleifehtffostneirtun

rettamcinagrolioS)MOS(

yletelpmocroyltrapsahtahtecafrusliosehthtaenebdnuofnigirolacigoloibfolairetamcinagroehT.nobrac%85tuobasiMOS.desopmoced

erutcurtslioSdoognetfosisliosdnalpufoerutcurtsehT.setagerggarostinuregralotniselcitrapliosfotnemegnarraehT

nacriadnaretawtahtsnaemhcihw,)ylluferacyawaderaelcsinoitategevecafrusehtfiylralucitrap(liosehthguorhtetalocrep ot .eganiarddnanoitnteterretawhtobedivorp

erutxeT .selcitrapdezis-dnasdna,tlis,yalcfonoitroporpevitalerehT

htliT .hguolproeohahtiwetavitlucotsiliosaysaewohfoerusaemasidnaerutcurtsotdetalerylesolcsisihT

noitazilitaloV .SdnaNrofyawhtapssoltnatropminA.erehpsomtaehtotmrofsuoesagnistneirtunfossolehT

yticapacgnidloh-retaW niaternacliosaretawhcumwohfoerusaemA

gnirehtaeW.ssecorplacisyhpdnalacigoloibybnwodnekorberaslairetamrehtodnaskcoryberehwssecorpehT

.gnirehtaewgniruddesaelererastneirtuN

Other educational material by PPI

In English:

� Field Handbook: Oil Palm Series Volume 1 – Nursery (109 p.)

� Field Handbook: Oil Palm Series Volume 2 – Immature (154 p.)

� Field Handbook: Oil Palm Series Volume 3 – Mature (135 p.)

� Pocket Guide: Oil Palm Series Volume 4 – Immature (154 p.)

� Pocket Guide: Oil Palm Series Volume 5 – Mature (154 p.)

� Pocket Guide: Oil Palm Series Volume 6 – Immature (154 p.)

� Pocket Guide: Oil Palm Series Volume 7 – Nutrient Deficiency Symptoms andDisorders in Oil Palm (Elaise guineensis Jacq.) (31 p.)

� International Soil Fertility Manual

Soil Fertility Management Slide Set (120 slides)

In Spanish:

� Guia de Bolsillo – Síntomas de Deficiencias de Nutrientes y Desórdernes inPalma Aceitera (Elaise gunieensis Jacq.) (31 p.)

In Bahasa Indonesia:

� Buku Petunjuk: Oil Palm Series Volume 7 – Gejala Defisiensi Hara danKelainan pada Tanaman Kelapa Sawit (Elaise guineensis Jacq.) (31 p.)

� Buku Saku: SebarFos – Proyek Pembangunan Pertanian Lahan Kering 1997-2000

For updates on new material, please request a copy of our color catalogue (availablein PDF format) from the PPI (ESEAP) office (refer to back cover).

For further information about this book or other matters relatingto tropical crop production and plant nutrition, contact:

Potash & Phosphate InstitutePotash & Phosphate Institute of Canada

East & Southeast Asia Programs126 Watten Estate RoadSingapore 287599Tel +65 468 1143Fax +65 467 0416E-mail tfairhurst@ppi-ppic.orgWebsite http://www.eseap.org

This book was produced in co-operation with:

ISBN: XXX-XX-XXXX-X

A toolkit for acid upland soil fertilitymanagement in Southeast Asia