Secondary and Micronutrient Secondary and Micronutrient ManagementManagement

Kent MartinSouthwest Area Crops and Soils Specialist

Kansas State Univ.

Essential NutrientsThirteen essential nutrients

– Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur

– Iron, manganese, boron, molybdenum, copper, zinc, and chlorine

• Nickel has recently been added

Micros are needed in much lower concentrations to ensure adequate supply

Essential MicronutrientsEssential Micronutrients Minor elements or trace elementsMinor elements or trace elements Increased interest in micronutrientsIncreased interest in micronutrients

Higher crop yields and micronutrient removal ratesHigher crop yields and micronutrient removal rates Declining soil organic matter, a major source of Declining soil organic matter, a major source of

most micronutrientsmost micronutrients N, P and K fertilizers contain lower amounts of N, P and K fertilizers contain lower amounts of

micronutrient impuritiesmicronutrient impurities Excessive levels can cause toxic effects on plantsExcessive levels can cause toxic effects on plants In Kansas: S, Zn, Fe, and Cl.In Kansas: S, Zn, Fe, and Cl. Other micronutrients: B, Mg, Cu, Mn, and Ni.Other micronutrients: B, Mg, Cu, Mn, and Ni.

Organic MatterOrganic Matter Important source of most micronutrients.Important source of most micronutrients. Simple organic compounds as chelates.Simple organic compounds as chelates. S, Zn and B deficiencies are more likely to S, Zn and B deficiencies are more likely to

occur in soils low in O.M.occur in soils low in O.M. Deficiencies of Cu and Mn are most Deficiencies of Cu and Mn are most

common in peat soils. common in peat soils.

Soil pHSoil pH Soil pH affects availability of Soil pH affects availability of

micronutrients.micronutrients. In general the solubility and availability of In general the solubility and availability of

micronutrients are greatest in acid soils micronutrients are greatest in acid soils and lowest in high pH calcareous soils.and lowest in high pH calcareous soils.

Exception is Mo.Exception is Mo. In some soils, high levels of soluble Fe, Al In some soils, high levels of soluble Fe, Al

and Mn may be toxic to plants.and Mn may be toxic to plants.

Sulfur (S)Sulfur (S)

Brian Lang, IA

Soil Situations and Climatic Conditions Aggravating Deficiency SymptomsCoarse textured soils (sandy soils)Low organic matter soilsCold, wet soils

Slow release of S from organic matterLow atmospheric deposition

No application fromManureOther fertilizers

Sulfur Deficiencies

10 kg SO4/ha = 3 lb S/acre

Sulfur Deposition

Corn Response to Sulfur

J. Sawyer, 2007

Comparison of Corn with and without Sulfur Application. Brian Lang

Corn Response to Sulfur Application

Sulfur in the SoilSulfur in the Soil Subsoil S may be significant.Subsoil S may be significant. Profile soil test for S, 0-24 inches, Profile soil test for S, 0-24 inches,

also good for nitrate and Cl.also good for nitrate and Cl.

Wheat S Rec. (Lb/A) = (0.6 × Y Goal) – (2.5 × % OM) – Profile Sulfur – Other Sulfur Credits

Corn and Sorghum S Rec. (Lb/A) = (0.2 × Y Goal) – (2.5 × % OM) – Profile Sulfur – Other Sulfur Credits

Soybean S Rec. (Lb/A) = (0.4 × Y Goal) – (2.5 × % OM) – Profile Sulfur – Other Sulfur Credits

Sulfur Fertilizer Recommendation

Zinc (Zn)Zinc (Zn)

ZincZinc Frequently deficient micronutrientFrequently deficient micronutrient Absorbed by plant roots as ZnAbsorbed by plant roots as Zn++++

Involved in the production of chlorophyll, Involved in the production of chlorophyll, protein, and several plant enzymesprotein, and several plant enzymes

Deficiency symptomsDeficiency symptomsMost distinctive in corn with new leaves out of Most distinctive in corn with new leaves out of

whorl turning yellow to white in a band whorl turning yellow to white in a band between the leaf midvein and marginbetween the leaf midvein and margin

Sensitive cropsCorn, sorghum

Soil SituationLow organic matter, high pH (>7.4), eroded soilCoarse texture, restricted rootingHigh P application in conjunction with borderline or low zinc availabilityHigh soil P alone does not create deficiency

Climatic ConditionsCool and wet soil

Zinc Deficiencies

Phosphorus and ZincPhosphorus and Zinc Excessive concentrations of P in the plant root result in the Excessive concentrations of P in the plant root result in the

binding of zinc within root cells.binding of zinc within root cells.

Large amounts of starter applied P can enhance Zn deficiency Large amounts of starter applied P can enhance Zn deficiency if soil Zn is low and no Zn fertilizer is applied.if soil Zn is low and no Zn fertilizer is applied.

PP22OO55 ZnZn YieldYield Leaf tissueLeaf tissue

lb/A *lb/A * bu/Abu/A P, %P, % Zn, ppmZn, ppm

00 00 101101 0.140.14 1212

00 1010 102102 0.160.16 2424

8080 00 7373 0.730.73 1010

8080 1010 162162 0.410.41 1717Adriano and Murphy

Kansas State University

PP22OO55 ZnZn B’castB’cast StarterStarter Lb / ALb / A Corn Yield (Bu/A)Corn Yield (Bu/A)

00 00 107107

00 1010 121121 115115

4040 00 121121 9393

4040 1010 139139 140140

St. Mary’s, KS – Kansas State University

P and Zn Effects on P and Zn Effects on Corn YieldsCorn Yields

Zinc Fertilizer Zinc Fertilizer RecommendationRecommendation

Corn, Sorghum and Soybeans Zinc Recommendation

Zn Rate = 11.5 – (11.25 × ppm DTPA Zn)If DTPA Zn > 1.0 ppm then Zn Rec = 0If DTPA Zn <= 1.0 ppm then Minimum Zn Rec = 1

Zn Rate (lb./acre) Yield (bu./acre)0 62

0.1 1310.3 1371.0 1403.0 142

Used 8-20-0 suspension with 2.5% clayDTPA extractable Zn = 0.3 ppm

Zinc in a Band—Corn Yield

Corn Yield—Zinc SourceZinc SourceZinc Source YieldYield

bu./acrebu./acreEDTAEDTA 136.6136.6

Nulex-ZnNulex-Zn 134.8134.8Zinc OxideZinc Oxide 127.5127.5

Zinc SulfateZinc Sulfate 138.3138.3Zinc rate was 0.3 lb. Zinc /acreZinc rate was 0.3 lb. Zinc /acre

Application MethodsApplication MethodsBroadcast

– Preferred to correct a low Zn soil test– 5 to 15 pound will increase soil test for a number of

years– Inorganic Zn is more economical than chelates at

these rates

Band– Very efficient method of applying Zn– 0.5 lb Zn/Acre of inorganic Zn is generally sufficient– Annual applications will be needed for low testing

soils

Chloride (Cl)

Chloride (Cl)Chloride (Cl) Wheat, corn, sorghum deficiencies in KansasWheat, corn, sorghum deficiencies in Kansas

Deficiencies most likely in higher rainfall areas with no Deficiencies most likely in higher rainfall areas with no K application history - central and eastern part of stateK application history - central and eastern part of state

Soluble, mobile anionSoluble, mobile anion

Addition of KClAddition of KCl Increased yields with high levels of available KIncreased yields with high levels of available K Reduced incidence of plant diseaseReduced incidence of plant disease Internal water relationships, osmotic regulation, enzyme Internal water relationships, osmotic regulation, enzyme

activation and other plant processesactivation and other plant processes

Grain YieldGrain Yield

ChlorideChloride Riley Co.Riley Co. Brown Co.Brown Co. Osage Co.Osage Co.

RateRate Site ASite A Site BSite B Site CSite C Site ASite A Site BSite B Site CSite C Site ASite A Site BSite B

lb/alb/a - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - -

00 7070 6464 107107 188188 123123 8787 133133 7979

2020 8484 6969 111111 191191 130130 9393 133133 8181

Soil test Soil test Cl, lb/a Cl, lb/a (0-24")(0-24")

99 1616 2424 2828 1414 2828 4040 6161

Chloride Fertilization on Corn in Chloride Fertilization on Corn in KansasKansas

Grain YieldGrain Yield

ChlorideChloride Marion Co.Marion Co. Saline CoSaline Co Stafford Co.Stafford Co.

RateRate Site ASite A Site BSite B Site ASite A Site BSite B Site CSite C Site DSite D Site ASite A Site BSite B Avg.Avg.

lb/alb/a - - - - - - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - - - - - - -

00 4545 8080 5151 8989 8383 7070 7373 6464 6969

2020 4747 8585 5454 8989 9090 7575 8080 7070 7474

Soil test Soil test Cl, lb/a Cl, lb/a (0-24")(0-24")

77 77 1414 2222 77 1414 77 1515 1212

*Average over either 12 or 16 varieties. Soil test Cl, lb/a (0-24")*Average over either 12 or 16 varieties. Soil test Cl, lb/a (0-24")

Chloride Fertilization on Wheat

Grain YieldGrain Yield

ChlorideChloride Marion Co.Marion Co. Brown Co.Brown Co. Osage Co.Osage Co.

RateRate Site ASite A Site BSite B Site CSite C Site DSite D Site ASite A Site BSite B Site ASite A Site BSite B

lb/alb/a - - - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - bu/a - - - - - - - - - - - - - - - - - -

00 8787 117117 6363 9292 102102 8787 125125 8888

1010 9494 139139 7171 113113 106106 9595 126126 9292

2020 9797 135135 7272 126126 111111 9696 125125 9696

Soil test Soil test Cl, lb/a Cl, lb/a (0-24")(0-24")

99 77 99 4343 77 99 5252 2929

Chloride Fertilization on Grain Chloride Fertilization on Grain Sorghum in KansasSorghum in Kansas

Chloride Fertilizer Chloride Fertilizer RecommendationRecommendation

Iron (Fe)

Mitchell Co.

Iron (Fe)

Iron (Fe)Iron (Fe) Iron in the plantIron in the plant

Catalyst in the production of chlorophyllCatalyst in the production of chlorophyll Involved with several enzyme systemsInvolved with several enzyme systems

Deficiency symptomsDeficiency symptoms Yellow to white leaf colorYellow to white leaf color Symptoms first appear on the younger leavesSymptoms first appear on the younger leaves Wide range of susceptibility of different cropsWide range of susceptibility of different crops

Sorghum, field beans and soybeans are more sensitive than corn Sorghum, field beans and soybeans are more sensitive than corn and alfalfaand alfalfa

Varieties differ within cropsVarieties differ within crops

Factors Affecting Iron AvailabilityFactors Affecting Iron Availability High soil pH.High soil pH. Soils with high salt contents.Soils with high salt contents. Cool, wet springs.Cool, wet springs. Poor soil drainage and aeration.Poor soil drainage and aeration. Susceptible crops/varieties.Susceptible crops/varieties. High concentrations of nitrate-N inhibit High concentrations of nitrate-N inhibit

conversion of Feconversion of Fe+++ +++ to Feto Fe++++, increasing , increasing severity of iron chlorosis.severity of iron chlorosis.

Fertilizer Sources of IronFertilizer Sources of Iron Deficiencies occur more frequently than most Deficiencies occur more frequently than most

other micronutrients in Kansasother micronutrients in Kansas Patchy or irregular appearance in the fieldPatchy or irregular appearance in the field Success with iron fertilization is difficultSuccess with iron fertilization is difficult

Difficulty in correcting Fe deficiency with soil-Difficulty in correcting Fe deficiency with soil-applied fertilizerapplied fertilizer Iron quickly converted to unavailable form.Iron quickly converted to unavailable form. Certain Fe chelate carriers (EDDHA) have been Certain Fe chelate carriers (EDDHA) have been

effective but have not been economical and may effective but have not been economical and may require multiple applicationsrequire multiple applications

Foliar Application most promisingFoliar Application most promising

Foliar ApplicationsFoliar Applications Applications must be done before plants are severely Applications must be done before plants are severely

damaged by chlorosis and may need to be repeateddamaged by chlorosis and may need to be repeated

Ferrous sulfate (1-2% solution) plus a wetting agent or Ferrous sulfate (1-2% solution) plus a wetting agent or one of several iron chelates/complexes may be usedone of several iron chelates/complexes may be used

Critical timingCritical timing Soybean - by the first trifoliate leafSoybean - by the first trifoliate leaf Sorghum - apply by the 6th leaf stageSorghum - apply by the 6th leaf stage

Common Iron FertilizersCommon Iron Fertilizers

Fertilizer Source

Iron Sulfate

Iron Chelates

Other Organics

Manure - best

Fe (%)

19-40

5-12

5-11

??

Manure sourceManure source IronIron ManganeseManganese BoronBoron ZincZinc CopperCopper

-----------------lb/wet ton--------------------------------------lb/wet ton---------------------

Dairy solidDairy solid 0.50.5 0.060.06 0.010.01 0.030.03 0.010.01

Swine solidSwine solid 19.019.0 1.091.09 0.040.04 0.790.79 0.500.50

PoultryPoultry 3.03.0 0.610.61 0.080.08 0.480.48 0.660.66

-----------------lb/1000 gal--------------------------------------lb/1000 gal---------------------

Dairy liquidDairy liquid 0.90.9 0.110.11 0.030.03 0.110.11 0.120.12

Swine liquidSwine liquid 2.52.5 0.230.23 0.060.06 1.031.03 0.620.62

Average animal manure micronutrient content of different animal sources

Micronutrients of Little Micronutrients of Little ConcernConcernNutrientNutrient ReasonReason

CalciumCalcium Very acid soils - Rare deficiencyVery acid soils - Rare deficiency

MagnesiumMagnesium Very acid, sandy soilVery acid, sandy soil

BoronBoron Dry, leached, low OM sands – Alfalfa or Dry, leached, low OM sands – Alfalfa or SoybeansSoybeans

ManganeseManganese High pH, High OMHigh pH, High OM

CopperCopper High OM, Highly weathered soilHigh OM, Highly weathered soil

MolybdenumMolybdenum Highly weathered acid soils – legumes Highly weathered acid soils – legumes – enough in seed?– enough in seed?

Kent Martinkentlm@ksu.edu

620-276-8286

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