Micronutrients in agriculture

Are they important?

Wim Bussink (NMI, www.nmi-agro.nl)

October 17, 2013

Nutriënten Management Instituut B.V.

Postbus 250, 6700 AG Wageningen

T: 088 8761280

E: nmi@nmi-agro.nl

I: www.nmi-agro.nl

• Micronutrients:

• importance, crop, animal, “human””

• deficiency & critical contents

• Micronutrient status NL, EU, others

• shortage in future

• soil testing & fertilizer

Lay out

• Needed in small quantities

• Necessary for growth and development (plant,

animal, human)

• Most are involved in protein synthesis/activation

• Deficiency symptoms chlorosis within leaves

• Deficiency < --- > toxicity

Stick deficiency photos

http://ppi-store.stores.yahoo.net/crnudeimco.html

Micronutrients

• Boron (B), H2BO3- NL

• Copper (Cu), Cl- NL

• Manganese (Mn), Mn2+ NL

• Zinc (Zn), Zn2+ NL

• Selenium(Se), SeO42- NL

• Iron (Fe), Fe2+ or Fe3+

• Molybdenum (Mo), MoO4-

• Nickel (Ni), Ni2+

• Chlorine (Cl), Cl-

Essential micronutrients (1)

Essential micronutrients, plants

molybdenum essential for nitrogen fixation, cofactor that

functions in nitrate reduction

iron component of cytochromes activates some

enzymes

nickel cofactor for enzyme functioning in nitrogen

metabolites

chlorine required for water-splitting step of

photosynthesis in water balance

Essential micronutrients

boron Cofactor in chlorophyll synthesis, may be

involved in carbohydrate transport and

nucleic acid synthesis

manganese Active in formation of amino acids,

activate some enzymes, required for

water-splitting step of photosynthesis

zinc Active in formation of chlorophyll,

activates some enzymes

copper Component of many redox and lignin-

biosynthetic enzymes

Crop Zn Fe Cu Mn B Mo

_____________________________________________________

beans h h h m

barley m m m m

broccoli m m h h

cabbage m m h m

canola h h h

carrot m m m m

corn h m m m m?

flax h m m

lettuce h h h m h

onion h h h h

potato m h

spinach h h h m h

s. beet m m h h h? m

wheat m h h

____________________________________________________

Sensitivity of some crops

http://eprints.nwisrl.ars.usda.gov/777/1/753.pdfDaves and Westermann, 1991

• Dependent of

• Crop type

• Growth stage

• Where it is measured

• Example Mn: potato

Critical contents

Nutrient Deficient Marginal Critical Suff High Very high

or toxic

Remarks Source

Mn (mg/kg) 40-100 YML before or start flowering 1

30-300 YML begin bloei 4

50-450 YML halverwege knolzetting 4

<30 30-60 >60 YML bij 20-25 cm gewashoogte 7

<30 30-100 >100 YML begin bloei 7

<20 20-100 >100 YML halverwege knolgroei 7

<20 20-100 >100 YML afsterven blad 7

<10 10-20 21-200 201-400 L midden seizoen, einde bloei 14

20-29 30-250 >250 L laat seizoen, halverwege knolgroei 14

7 40 L 15

Example Boron

Shortage:

Sugar beet:

death of growing points in

center of plant, brown fibrous

patches on leaf stems

decrease of sugar content

Poorer development of

maize ear

less nodule development in

legumes

Example: Mn shortage

Also sensitive crops

• oil seed rape

• peas

• beans

• cabbage

• carrots

• lettuce

• onions

Deficiency yield depression up to:

• 20% potato

• 10% sugar beet

• 50% grain

INPUT Mn; strong decrease due to:

• Decrease of Mn containing crop protection products

(maneb, mancozeb)

• Fertilizer less “polluted” with Mn

OUTPUT Mn

• Circa 200 g Mn/ha

OUTPUT > INPUT deficiency possible

especially high pH soils

Induced shortage due to Round-Up use? IFS SympRomheld (2004)

Mn actual

Purdue Work Don Huber

Root uptake Translocation to shoot

Effect of glyphosphate: 2.5% of recommended rate

Examples Mn

Zn

• Enzymes, reproduction, immune defense system

appetite

• Small body reserve• Muscles, bones

• Shortage effects: fast

Cu

• Blood & bone formation, resistance

• Large body reserve

Animals (cattle): Zn and Cu

Se

• Resistance, less muscle damage,

reproduction/fertility,

• Large body reserve• enzyme GSH-Px (red blood cells, organs & tissue)

Co

• Essential for Vit B12

• small body reserve

• liver

Animals (cattle): Se and Co

http://www.oxfordjournals.org/our_journals/tropej/online/mcnts_chap10.pdf

http://www.fao.org/docrep/013/am027e/am027e00.pdf

Micronutrient status NL, EU,

others

Zn deficiency worldwide(mining stocks about 30 yr!!!)

In Europe: Turkey has Zn deficiency problems

Boron deficiency worldwide (after Shorrocks, 1997)

China:Se deficiency as well as to

rich soils China

Europe:Generally to low Finland

fertilization program for over 20

years

Bron: Schaarste van micronutriënten, in bodem,

voedsel en minerale voorraden, 2012

Number of years of supply for essential mineral nutrients (vertical axis)

based on current reserves and consumption levels (data source: USGS,

2011).

Jongvee Vaarzen Oudere koeien Dekkingsgraad (%) <1

jaar >1

jaar 14

dgn 100 dgn

200 dgn

300 dgn

drg 14

dgn 100 dgn

200 dgn

300 dgn

drg

Zomer 198 199 216 210 180 221 191 199 198 181 212 199 Zink

Winter 198 178 216 209 190 229 191 199 198 180 221 199

Zomer 216 72 236 226 168 201 38 205 202 168 184 40 Selenium

Winter 216 71 231 220 161 203 38 200 196 161 186 40

Zomer 139 77 315 319 199 153 44 287 302 216 152 46 Koper

Winter 151 68 340 343 210 175 47 309 324 229 175 50

Zomer 184 99 610 509 459 445 73 503 445 424 414 73 Kobalt

Winter 184 98 594 494 440 434 73 488 431 407 404 73

Often supplementation in dairy cattle

farming: not only in NL

Factors involved in micronutrient

availability

• Total amount

• pH

• Organic matter

• CEC

• Oxides

• Redox potential

• Temperature

• Interaction with

other nutrients

Factors involved in micronutrient

availability

• Soil water content

• Microbial activity

• Mycorrhizas

• Root growth

• Root induced

changes

(phytosiderophores)

• Heavy metals Cu, Ni and Zn

– minimise increase

• Food safety

• Minimise fertilisation costs

– marginal profits in agriculture

• Scarce minimise use:

– stocks Zn, Cu & 30-50 years (USG, 2011)

Requirement of:

• (High quality) testing at a low price

– From single nutrient towards multi-nutrient extraction

Soil and plant testing

• Boost after 1945

• “Aggressive extractants” to measure anything

Variation in micronutrient content of soil and soil solution

Big variation in soil

Element Total content, mmol kg-1

Concentration in soil solution, M

total Ionic form

B 0.100 - 25 1 – 100 1 – 100

Mo 0.002 – 0.38 0.01 – 1.5 0.001 – 1.5

Cu 0.015 – 5.08 0.05 – 0.6 10-5

– 101

Zn 0.05 – 11.6 0.03 – 3.8 10-5

– 103

Mn 0.365 – 167 0.1 – 790 10-1

– 104

Fe 3.5 – 1800 0.3 – 17.1 10-4

– 101

Ni 0.0035 - 6.3 0.01 - 0.425 10-3

– 10-1

Co 0.015 – 5 0.005 - 1.5

Se 0.0008 – 0.25 0.0001- 0.1 10-4

• Trial and error research

Many different soils

• Many (complex) extractants used different fractions• Empirical validation

• Regional basis

• Results outdated NL, Cu & Co 50 yrs old

An overview of extractants used

Many different procedures

1 component 2 components 3 or more components

Water Mehlich 1 Mehlich 2

Dilute salts (CaCl2, NaCl, KCl, Mg(NO3)2 Morgan Mehlich 3

Hot water Wolf-Morgan AAAc-EDTA

DTPA AB-DTPA DTPA+CaCl2+triethanolamine

EDTA Ammonium oxalate CH3COOH+ NH4Cl+citric acid+ HCl

EDDHA CaCl2 +DTPA (ie CAT)

Pyrophosphate EDTA+(NH4)2CO3

Anorganic acids of different strength

(HCl, HNO3, H3PO4, H2SO4)

Citric acid + EDTA

Organic acids of different strength

(citric, acetic)

Hydroquinone

Triethanolamine

• Extractant information

– what is directly available (intensity) (ie 0.01 M CaCl2)

– what can come readily into solution (capacity)

• (strong) acid spectroscopic tech., NIR/MIR/XRF

– multi-nutrient and ICP(-MS) Interactions

• Modelling chemical processes solid phase/solution

• Field and pot trials

New Approach

2011-2014 STW research project Cu, Mn, B, Se

2 AIO’s WU, NMI, Blgg, AKZO, PA, PZ

• Micronutrients, important but often underestimated

• Plant, animal and humans

• Shortage now in many parts of the world

• Diminishing stocks

• To much focus on N, P and K

• Soil and plant testing

Final remarks