Fertilizing for No-Fertilizing for No-tilltill

Kent MartinKent Martin

Southwest Research Southwest Research Extension CenterExtension Center

Kansas State UniversityKansas State University

OverviewOverviewNitrogenNitrogen

Loss mechanismsLoss mechanismsNo-till considerationsNo-till considerations

RequirementsRequirements

Nitrogen use efficiencyNitrogen use efficiency

Management FactorsManagement Factors

PhosphorusPhosphorusBackgroundBackground

Plant uptakePlant uptake

RecommendationsRecommendations

OverviewOverview

PotassiumPotassiumPlant uptakePlant uptake

RecommendationsRecommendations

Stratification of P and KStratification of P and K

Starter considerationsStarter considerations

SummarySummary

NitrogenNitrogen

Primary crops in Kansas use large Primary crops in Kansas use large amounts of Namounts of N

Soils contain thousands of pounds of NSoils contain thousands of pounds of NNaturally deficient in most agricultural soilsNaturally deficient in most agricultural soils

Environmental concern due to lossEnvironmental concern due to loss

How much is available?How much is available?

Why is some not available?Why is some not available?

We make assumptions for the best We make assumptions for the best estimateestimate

NitrogenNitrogenSoil organic matter – “storage mechanism” for Soil organic matter – “storage mechanism” for NN

Plant and animal residuePlant and animal residue

Decomposed organic materialsDecomposed organic materials

True organic matter – persistent decomposition True organic matter – persistent decomposition productsproducts

AssumptionsAssumptionsRange from 1-4% average is 2.2% in KansasRange from 1-4% average is 2.2% in Kansas

2,000,000 pounds x 2.2% = 44,000 pounds soil organic 2,000,000 pounds x 2.2% = 44,000 pounds soil organic mattermatter

If soil organic matter is 5% N then 44,000 pounds x 5% = If soil organic matter is 5% N then 44,000 pounds x 5% = 2,200 pounds N in soil2,200 pounds N in soil

We have a lot of N from soil organic matter!! Why We have a lot of N from soil organic matter!! Why are our crops typically deficient??are our crops typically deficient??

NitrogenNitrogen

How do we use it??How do we use it??

MineralizationMineralizationConversion of this organic matter Conversion of this organic matter (proteins and amino acids) by microbes(proteins and amino acids) by microbes

R-NHR-NH22 + H + H22O → NHO → NH33 + R-OH + Energy + R-OH + Energy

Requires airRequires air

Rate is sensitive to temperature and Rate is sensitive to temperature and moisturemoisture

Occurrs when it is cold, but not frozenOccurrs when it is cold, but not frozen

NitrogenNitrogen

Immobilization – opposite of mineralizationImmobilization – opposite of mineralizationOccurs with an abundance of carbonOccurs with an abundance of carbon

Microbial populations increase to utilize Microbial populations increase to utilize carboncarbon

Inorganic N (available) is used for this processInorganic N (available) is used for this process

Transforms to organic N and is unavailableTransforms to organic N and is unavailable

C:N ratio controls the balanceC:N ratio controls the balance<25:1 = net mineralization (N released)<25:1 = net mineralization (N released)

>25:1 = net immobilization (N tied up)>25:1 = net immobilization (N tied up)

NitrogenNitrogenCommon C:N ratiosCommon C:N ratios

Source

Microorganisms

Soil O.M.

Alfalfa

Soybean Residue

Rotted Manure

Green Rye

Cornstalks

Small grain straw

Grain Sorghum

Sawdust

% Carbon

50

52

40

---

--

--

40

40

40

40

% Nitrogen

6.2

5.0

3.0

---

--

--

0.7

0.5

0.5

0.1

C:N Ratio

8:1

10:1

13:1

15:1

<20:1

36:1

60:1

80:1

80:1

400:1

Mineralization

Immobilization

NitrogenNitrogenWhat does this mean for no-till??What does this mean for no-till??

Crop residues on the soil surface causes Crop residues on the soil surface causes immobilizationimmobilization

Consider placement to overcome immobilizationConsider placement to overcome immobilizationInject>surface band>broadcastInject>surface band>broadcast

Starter placement works well (caution seed placed rates)Starter placement works well (caution seed placed rates)

Some crop residues (<25:1 C:N) causes Some crop residues (<25:1 C:N) causes mineralizationmineralization

Previous crop adjustments for cool season cropsPrevious crop adjustments for cool season cropsCorn, wheat, soybeans = 0; Sorghum, sunflowers = Corn, wheat, soybeans = 0; Sorghum, sunflowers = +30; Fallow = -20 (0 if profile nitrate test is used)+30; Fallow = -20 (0 if profile nitrate test is used)

Previous crop adjustment for warm season cropsPrevious crop adjustment for warm season cropsCorn, wheat, sorghum, sunflowers = 0; Soybeans = -40; Corn, wheat, sorghum, sunflowers = 0; Soybeans = -40; Fallow = -20 (0 if profile nitrate test is used)Fallow = -20 (0 if profile nitrate test is used)

Nitrogen - LossNitrogen - Loss

N loss mechanismsN loss mechanismsRunoffRunoff

LeachingLeaching

VolatilizationVolatilization

DenitrificationDenitrification

Nitrogen - LossNitrogen - LossRunoff – physical movement off fieldRunoff – physical movement off field

Slope adds riskSlope adds risk

Factors that prevent movement into soilFactors that prevent movement into soilFrozen soilsFrozen soils

No-till surface residue minimizes this lossNo-till surface residue minimizes this loss

Leaching – downward movement of Leaching – downward movement of nitratenitrate

Course textured soilsCourse textured soils

Significant rainfall or over irrigationSignificant rainfall or over irrigation

N in nitrate form adds riskN in nitrate form adds risk

Extreme early applicationExtreme early application

Nitrogen - LossNitrogen - LossDenitrification – loss of N from nitrate as a Denitrification – loss of N from nitrate as a gasgas

Fine textured soil, low permiabilityFine textured soil, low permiability

Warm, moist conditions drive itWarm, moist conditions drive it

Slow conversion to nitrate decreases loss riskSlow conversion to nitrate decreases loss risk

Over application of irrigation waterOver application of irrigation water

Volatilization – loss of ammonia from urea Volatilization – loss of ammonia from urea (gas)(gas)

Caused by evaporation of water on warm Caused by evaporation of water on warm windy dayswindy days

Can be a problem in no-till or grassCan be a problem in no-till or grass

High pH and free ammonia increase riskHigh pH and free ammonia increase risk

Nitrogen - RequirementsNitrogen - RequirementsTypical equationTypical equation

N rec = (yield goal x coefficient) – creditsN rec = (yield goal x coefficient) – credits

CoefficientsCoefficientsCorn and sorghum = 1.6Corn and sorghum = 1.6

Wheat = 2.4Wheat = 2.4

Sunflowers = 0.075Sunflowers = 0.075

CreditsCreditsPrevious crop adjustmentPrevious crop adjustment

Soil organic matter (% x 20 warm season, % x 10 Soil organic matter (% x 20 warm season, % x 10 cool season)cool season)

24 inch soil test24 inch soil test

ManureManure

Irrigation waterIrrigation water

Nitrogen - RequirementsNitrogen - Requirements

Example calculationExample calculation180 bu corn needs 288 lb N (180*1.6)180 bu corn needs 288 lb N (180*1.6)

2% organic matter contributes 40 lb N 2% organic matter contributes 40 lb N (2*20)(2*20)

In rotation with soybean contributes 40 lbIn rotation with soybean contributes 40 lb

Profile nitrate test has 30 lb availableProfile nitrate test has 30 lb available

N need is 178 lb N per acreN need is 178 lb N per acre178=288-40-40-30178=288-40-40-30

No-till adjustmentsNo-till adjustmentsAdd 20-30 lb NAdd 20-30 lb N

Nitrogen Use EfficiencyNitrogen Use EfficiencyWhat you apply and what you utilizeWhat you apply and what you utilize

Typically low – we never use 100% Typically low – we never use 100% of what we applyof what we apply

Global effort to increase efficiencyGlobal effort to increase efficiencyFertilizer sourceFertilizer source

Application timingApplication timing

Fertilizer additivesFertilizer additives

Tools for rate determinationTools for rate determinationSoil testSoil test

SensorsSensors

Nitrogen Use EfficiencyNitrogen Use Efficiency

Typically low – average <50%Typically low – average <50%N Rate N Uptake Grain Yield Harvest Percent N Increment Increment lbs/a lbs/a bu/a Index Recovery Response Recovery

0 91 98 0.32 --- --- --- 40 S 106 115 0.36 38% 17 38% 70 S+sd 124 133 0.38 47% 18 60%100 S+sd 135 149 0.42 44% 16 37%130 S+sd 156 164 0.40 50% 15 70%160 S+sd 161 172 0.46 44% 8 17%190 S+sd 177 177 0.43 45% 5 53%220 S+sd 160 154 0.43 31% - 23 ---

200 pp 173 162 0.41 41% --- ---

N response to dryland corn: Manhattan, 2006N response to dryland corn: Manhattan, 2006

Nitrogen – Management Nitrogen – Management FactorsFactors

How do we best utilize our N?How do we best utilize our N?Timing – as close to utilization as possibleTiming – as close to utilization as possible

Rate – determine accurate application ratesRate – determine accurate application rates

Placement – apply below the soil surface if Placement – apply below the soil surface if possiblepossible

Fertilizer source – AA, UAN, UreaFertilizer source – AA, UAN, Urea

Specialty fertilizers – ESNSpecialty fertilizers – ESN

Fertilizer additivesFertilizer additivesAgrotain – urease inhibitorAgrotain – urease inhibitor

N-Serve – nitrification inhibitorN-Serve – nitrification inhibitor

Super U – urease and nitrification inhibitorSuper U – urease and nitrification inhibitor

Nitrogen – Management Nitrogen – Management FactorsFactors

PhosphorusPhosphorusAn environmental concernAn environmental concern

P concentration in top 3-4 inches controls P concentration in top 3-4 inches controls dissolved P in runoff (a concern for us???)dissolved P in runoff (a concern for us???)

Soils contain 300 to 2,000 lb/a P, most is Soils contain 300 to 2,000 lb/a P, most is unavailableunavailableSupplied to plant roots by diffusion Supplied to plant roots by diffusion (~95%)(~95%)

Diffusion is slow as compared to other Diffusion is slow as compared to other nutrientsnutrientsMoves short distances (1/8 inch or 1+ inch, Moves short distances (1/8 inch or 1+ inch, 1954 data)1954 data)Early plant P concentration is affected by Early plant P concentration is affected by proximity and rateproximity and rate

PhosphorusPhosphorus

Why do we want P uptake in a young Why do we want P uptake in a young plant?plant?

From: Fertilizing for Irrigated Corn, 2008 From: Mengel and Barber

PhosphorusPhosphorus

Placement is importantPlacement is importantRoots flourish where P is appliedRoots flourish where P is applied

Most preferred placement is starterMost preferred placement is starter

Drew 1975

PhosphorusPhosphorus

What affects P availabilityWhat affects P availabilityCrops GrownCrops Grown

Clay contentClay content

Time and method of P applicationTime and method of P application

AerationAeration

CompactionCompaction

MoistureMoisture

TemperatureTemperature

Phosphate status of the soilPhosphate status of the soil

Other nutrientsOther nutrients

Soil pHSoil pH

Phosphorus - Phosphorus - RecommendationsRecommendations

Sufficiency and build/maintainSufficiency and build/maintain

PotassiumPotassium

Not an environmental concernNot an environmental concern

Very little movement (1/4 in.)Very little movement (1/4 in.)

Supplied to plant roots through Supplied to plant roots through diffusiondiffusion

Very slowVery slow

In extremely sandy soils with flooding, In extremely sandy soils with flooding, some can be leached (Concern for us??)some can be leached (Concern for us??)

Very salty fertilizer sourcesVery salty fertilizer sourcesBand placements should not be with the Band placements should not be with the seedseed

PotassiumPotassium Very rapid uptake of KVery rapid uptake of K

PotassiumPotassium

What limits K What limits K uptakeuptake

Poor aerationPoor aeration

CompactionCompaction

Very dry or Very dry or very wet soilsvery wet soils

Cold Cold temperaturestemperatures

PotassiumPotassium

Temperature and potassium responseTemperature and potassium response

Potassium - Potassium - RecommendationsRecommendationsSufficiency and build/maintainSufficiency and build/maintain

No-till factors affecting P No-till factors affecting P and Kand K

Cold wet soil in spring limits plant Cold wet soil in spring limits plant growth, P and K diffusion, and thus growth, P and K diffusion, and thus uptakeuptake

Reduced soil moisture loss/increased Reduced soil moisture loss/increased water infiltration improves uptake water infiltration improves uptake and efficiencyand efficiency

Decreased erosion decreases Decreased erosion decreases nutrient lossnutrient loss

Nutrient StratificationNutrient StratificationStratify means to form layers or strataStratify means to form layers or strata

Nutrient StratificationNutrient Stratification‘‘Layers’ of nutrient concentrationsLayers’ of nutrient concentrations

The concentrations typically decrease The concentrations typically decrease with depth causing nutrient enrichment with depth causing nutrient enrichment in the surface layers in the surface layers

0-3 in.

3-6 in.

6-9 in.

9-12 in.

12-24 in.

Nutrient Stratification Nutrient Stratification DevelopmentDevelopment

Not a concern in the pastNot a concern in the pastConventional heavy tillage provided deep Conventional heavy tillage provided deep mixing so stratification did not developmixing so stratification did not develop

No-till/reduced till situationNo-till/reduced till situationMobile nutrients do not stratify like Mobile nutrients do not stratify like immobile onesimmobile ones

Inadequate soil mixing to alleviate Inadequate soil mixing to alleviate stratificationstratification

Surface application of nutrients (manure)Surface application of nutrients (manure)

Nutrient uptake and surface decompositionNutrient uptake and surface decompositionExplained nextExplained next

Nutrient Stratification Nutrient Stratification DevelopmentDevelopment

Nutrient uptake and Nutrient uptake and decomposition/depositiondecomposition/deposition

Assume a 150 bu/ac corn cropAssume a 150 bu/ac corn crop

Dale Leikam

Stratification of PStratification of P

KSU, 2009

Tillage and Stratification Tillage and Stratification of Pof P

Mallarino, ISU

Tillage and Stratification Tillage and Stratification of Kof K

Mallarino, ISU

Potassium StratificationPotassium Stratification

Long-term tillage in Indiana 1975-1994 Long-term tillage in Indiana 1975-1994 (Holanda)(Holanda)

Gordon, KSU

Remedies for Remedies for StratificationStratification

TillageTillageSoil mixing will create uniform Soil mixing will create uniform distribution of nutrientsdistribution of nutrients

May not be advisableMay not be advisable

Nutrient applicationNutrient applicationAvoid surface applicationAvoid surface application

Deep applicationDeep application

**Do We Need To Remedy It??****Do We Need To Remedy It??**

Effect of Placement on Effect of Placement on YieldYield

Mallarino, ISU

Effect of Placement on Effect of Placement on YieldYield

Mallarino, ISU

Effect of Placement on YieldEffect of Placement on Yield

EffectEffect Pr > FPr > F

StarterStarter 0.010.01

PlacementPlacement 0.310.31

RateRate 0.750.75

Starter × PlacementStarter × Placement 0.110.11

Starter × RateStarter × Rate 0.830.83

Placement × RatePlacement × Rate 0.660.66

Starter × Placement × Starter × Placement × RateRate

0.180.18Proc Mixed

Starter by Placement by Rate Factorial 2006, Starter by Placement by Rate Factorial 2006, 2007, 20082007, 2008

Effect of Placement on Effect of Placement on YieldYield

Most studies mention that there was Most studies mention that there was not a benefit from deep band not a benefit from deep band application of P and an inconsistent application of P and an inconsistent benefit from Kbenefit from K

Note: There is not a penalty for deep Note: There is not a penalty for deep banding P or K. This may be equally banding P or K. This may be equally importantimportant

Provides options for producersProvides options for producers

Placement and Soil TestPlacement and Soil Test

Placement options clearly alter vertical Placement options clearly alter vertical distributiondistribution

What about lateral distributionWhat about lateral distribution Broadcast maintains uniform lateral Broadcast maintains uniform lateral

concentrationconcentration Starter alters lateral uniformity, but Starter alters lateral uniformity, but

typically at low levelstypically at low levels Deep banding increases vertical and lateral Deep banding increases vertical and lateral

variability due to depth and higher rate of variability due to depth and higher rate of application.application.

0

10

20

30

40

50

60

70

0 10 20 30 40 50Soil P Concentration (mg kg-1)

Dep

th (

cm) Check

34.8 Bdcast

8.7 Start, 26.1 Bdcast

8.7 Start, 26.1 Deep Band, 17.4on Soybean

0

5

10

15

20

25

30

0 10 20 30 40 50Soil P Concentration (mg kg-1)

Dep

th (

in) Check

80 Bdcast

20 Start, 60 Bdcast

80 Deep Band

20 Start, 60 Deep Band

20 Start, 60 Deep Band, 40 onSoybean

Effect of P Placement on Effect of P Placement on SoilSoil

Effect of P Placement on Effect of P Placement on SoilSoil

Depth (cm)Depth (cm) BroadcastBroadcast Deep BandDeep Band LSD*LSD*

--------------------------Scandia---------------------------------------------------Scandia-------------------------

0-7.60-7.6 28.528.5 13.413.4 12.1312.13

7.6-157.6-15 9.59.5 21.421.4 9.729.72*=Protected LSD; Calculated using Proc mixed (alpha=0.1)

Soil test P concentration mean (taken from under the row)

Depth (cm)Depth (cm) CheckCheck BroadcastBroadcast Deep BandDeep Band

--------------------------Scandia (CV, %)---------------------------------------------------Scandia (CV, %)-------------------------

0-7.60-7.6 66.866.8 33.033.0 9.19.1

7.6-157.6-15 23.623.6 19.919.9 86.986.9

Soil test P Coefficient of Variation (taken from under the row)

Starter fertilizerStarter fertilizer Great when an early delay cannot be Great when an early delay cannot be

offset during the seasonoffset during the season Useful if nutrients are not in the seedling Useful if nutrients are not in the seedling

root zone – too deep or on the surfaceroot zone – too deep or on the surface Cold wet conditions limit uptakeCold wet conditions limit uptake Late planting datesLate planting dates Most frequent response from no-till Most frequent response from no-till

managementmanagement Seldom enough in low testing soilsSeldom enough in low testing soils Apply no more than 8-10 lb N+K with Apply no more than 8-10 lb N+K with

seed!!seed!!

SummarySummary

Nitrogen is the most frequent limiting Nitrogen is the most frequent limiting nutrientnutrient

Concerns for no-tillConcerns for no-tillMinimize contact of N fertilizer with residueMinimize contact of N fertilizer with residue

Avoid loss conditions – sources, placement, Avoid loss conditions – sources, placement, timing, rate, additivestiming, rate, additives

Adjust cool season rates for no-tillAdjust cool season rates for no-till

Increase N use efficiency through all Increase N use efficiency through all management factorsmanagement factors

SummarySummaryPhosphorus – second most limiting in our Phosphorus – second most limiting in our areaarea

Starter may give best response in no-tillStarter may give best response in no-tillWon’t be useful for raising soil test levelWon’t be useful for raising soil test level

Needed early in the growing seasonNeeded early in the growing season

Can become highly stratified after years of Can become highly stratified after years of no-tillno-till

Not a significant concernNot a significant concern

Potassium – not a big concern in our areaPotassium – not a big concern in our areaNeeded early in growing seasonNeeded early in growing season

Can become highly stratifiedCan become highly stratifiedMore frequent response than with PMore frequent response than with P

Use caution with starter applicationUse caution with starter application

Questions?Questions???