Tractor machinery and equipment for Conservation Agriculture

Introduction

Crop production in (sub)tropical areas was heavily influenced by European developments

Introduction of machinery without critically testing and validating them

Under tropical circumstances the destructivepotential of ploughs and particularly discs is increased

Traditional land preparation

Clearing of the land(Burning of fallow vegetation or residues)Primary tillageSecondary tillageCrop management activities: weeding, ridging, breaking crusts, etc.

Reasons for soil tillage

TraditionPreparation of the seedbedControl of weeds and pestsEnhancement of soil water storage and retentionWarming-up of the soil

Functions of soil tillage

Prepare seedbedManage crop residuesIncorporate fertilizers and agro-chemicalsControl weedsDecompact dense layersIncrease water infiltrationShape the soil surface (levelling, ridging)

Effects of badly chosen tillage practices

Tillage system

Reduction of vegetative cover

Compaction of underlying layerPulverization of

surface layer

Reduction of water infiltration

Bad root development

Low yieldsIncrease in run-off

ErosionInefficient use of

water and fertilizers High production costs

Winderosion

Pollution

Residues left with different land preparation activities

Residues after harvest 80-95 %

Mouldboard plough 0-15 %

Plough and chisel 0-10 %

Discs (2 operations) 15-20 %

Chisel (2 operations) 30-40 %

Cultivator (2 operations) 40-50 %

Cultivator (1 operation) 50-70 %

Direct seeding 80-95 %

Disadvantages of tillage

Loss of soil moistureLimits water infiltration through surface sealingDestroys the soil structureIncreases erosion riskIncreases operational costHigh demand on power, time and equipment

Conservation Agriculture

Alternative to conventional tillage, through

permanent soil coverno mechanical soil disturbancecrop rotation and cover crops

Functions of Conservation Agriculture

Conserve the soilSoil moisture retentionImprove the soil’s productivityReduce machinery costsReduce time input

Advantages of Conservation Agriculture

Increases organic matterIncreases water Improves soil structureIncreases crop yieldsAllows more time off for other activitiesMore cost-effective

Tools and equipment used in Conservation Agriculture

Ploughs, chisels and subsoilersCover crop and weed managementDirect seeding

Plough

Mainly used for primary tillage

DisadvantagesNeeds high powerCreates plough panLoss of soil moistureBrings weed seeds to the surface

No regular use under CA

Chisels or rippersTool for minimum or reduced tillage

DisadvantagesPoor weed controlClogging up with residuesNeeds proper soil moisture (crumbling point or dryer)Lifting stones/clods

SubsoilerTo break hard or compacted soil layers

DisadvantagesNeeds lot of powerWorn points reduce effectWater infiltration will not improve a lot when used improperlyTo be used in dry soils only

SubsoilerUnder Conservation Agriculture

Subsoilers should:work under crop residues (have cutting disks)Not lift clods to the soil surface requiring subsequent tillage (shanks bent to the side)Be only considered as exceptional repair tool

Subsoiler

Cover crop and weed management

Mechanical managementKnife rollersMowers and choppersMechanical weeding

Chemical management

Mechanical managementKnife rollers or chopping rollers

To flatten and crush the weed or cover crop

AdvantagesSimple and relatively cheap

DisadvantageNeeds proper management to avoid regrowth

Alternative crushers

SledgeTree trunkCulvertOld car tyresModified disk harrows

Alternative crushers

Mechanical managementMower/Shredder

To cut or chop residues

AdvantageAvoids clogging up of the seeding equipmentControls pests

DisadvantageRapid decompositionPossible resprouting

Mechanical managementMower/Shredder

Mechanical managementStraw management

Straw choppers on a combine:

AdvantageAvoids clogging up of the seeding equipmentGood spreading

DisadvantageHigh power demandPossible “hairpinning”

Mechanical managementStraw management

Straw choppers on a combine:

AdvantageLow power demandSlow decompositionLess “hairpinning”

DisadvantageFew commercial productsDifficulties in spreading

Mechanical weed Management

Weeders for residue coverHave a cutting discHave few hoes with wide blades

orare of rolling type

Mechanical weed Management

Chemical management

Use of herbicides to desiccate or kill the vegetation

AdvantageEasy and quick

DisadvantageSometimes expensiveHealth and environmental risks - needs proper training

Functioning of sprayers

TankPumpControls and filtersSpray lines/boomNozzle (hydraulic, rotary)

Different sprayers

Hydraulic nozzleRotary nozzle/low volume

Point sprayer(single nozzle)

Boom sprayerShieldedsprayer/row crops

Direct seeding

Broadcast seeding

Planting stick or hand jab planter

Animal traction direct planters

Tractor direct seed-drills and planters

Direct seeding- broadcast -

Broadcasting using a fertilizer spreaderused for small grain and cover crops:Seed is “walked” through mulch coverusing disk harrows set straight

Direct seeding foranimal traction and tractorsBasic design Row cleaner

Cutting discFertilizer coulter

hoedisc

Seed coulterdischoepunch

Seed fixing wheelPress wheel

Row cleaner

For heavy difficult mulchFor delicate seedsIn cold climates to warm up the soil

Cutting disc

Soil conditions: texture, resistance to penetration, humidity and porosityStraw and residue condition: resistance to be cut, humidity, quantity and managementSeeder: weight and dynamicsDisc: size/shape/profile

To get a good result

Work during the warmest hours of the dayWork when the straw is either green or completely dryOperate when soil is friableWith animal traction never try to seed when you have more than 5 tons of dry matter as soil cover

Insufficient cutting of the residues

Accumulation of residues between different parts of the seederIrregular spacing or complete absence of seedsIrregular germinationFertilizer deposition problems

Furrow openers

Punch type injection

chisel tine or hoe

single discs at an angle to the furrow

double discs, either the same diameter or not and placed in an angle forming a "V" to each other

Three basic slot / furrow shapes

V-shaped slot(double disc)U-shaped slot(Single disc, hoe,rotating knifeopeners)Inverted T-shaped slot

(Baker-Boot, hoes)Cross slot

Daily moisture loss from different slots:V 3.7%U 2.4%Inverted T 1.7%

Double disc coulter

Create V-shaped furrowsAngle about 10 degreesResidue handling easySimple construction and maintenance freeImproved action with different disc-diameters and offset discs (better cutting, self cleaning)

Double disc coulter

Disadvantages

Needs high penetration forcesIntolerance to sub-optimal soil conditionsTendency to ‘tuck’ residues into the slot(hairpinning)Concentration of seeds and fertilizers

Single disc coulter

Produce U-shaped slotSimple and robustCompact (often used for small grain seeddrills)Good residue handling

Single disc coulter

DisadvantageHigh penetration force requiredConsiderable soil movement (depending on angle)

Hoe openers

AdvantagesLow costLess affected by forward speedGood penetration, thus ideal for animal traction and dry soilNo “hairpinning”

Hoe openers

DisadvantagesProblems with stones and obstaclesRequires good cutting disc for long residues Considerable soil movement depending on shape and width

Strip till

Create U-type slots; used for strip tillage for transplanting or for some no-till seeddrillsProblems with long straw (depend on design)Considerable soil movement

Inverted T-opener

AdvantagesNo compaction of the soilSelf-closure of the slotConstant seeding depthExcellent for grassland

Inverted T-opener

DisadvantagesConsiderable wear on sandy soilsNo proper furrow opening onloose soilsDifficult residue handling(requires cutting disc)

Cross slot

AdvantagesIdeal germinationconditions for seedEffective separation ofseed and fertilizerLow draft requirementGood residuehandling, nohairpinning problem

Cross slot

DisadvantagesConsiderablewear on sandysoilsExpensive

Rolling Punch Injection

AdvantagesGood residuehandling

DisadvantagesClogging onsticky soils

Metering/Seedplates

Different sizes for small and big seedsActivated by the movement of one of the wheelsDifferent systems: seed plates with holes, chambers, spoons, mechanic release, pneumatic

Metering

Interesting feature: combined metering systems for drill seed and precision planting on the same machine

Precision Planters: Tractor

Seed drills: Tractor

Thank you

© Photos Theodor Friedrich/FAO