Managing Manure for Managing Manure for Crop Production Crop Production when Feeding DDGSwhen Feeding DDGS

Kyle JensenKyle Jensen

ISU Extension Field Specialist-CropsISU Extension Field Specialist-Crops

Feeding DDGS Changes the Feeding DDGS Changes the Manure Nutrient ContentManure Nutrient Content

Crude Protein is higherCrude Protein is higher Phosphorus is higherPhosphorus is higher

Rule of ThumbRule of Thumb DDGS contain about 3 times the nutrient DDGS contain about 3 times the nutrient

analysis of cornanalysis of corn

Corn and Soybean Corn and Soybean requirementsrequirements

NitrogenNitrogen PhosphorusPhosphorus PotassiumPotassium

Calcium, Magnesium, SulfurCalcium, Magnesium, Sulfur

Fe, Mn, Zn, Cu, Ni, Mo, B, ClFe, Mn, Zn, Cu, Ni, Mo, B, Cl

How Much N do I needHow Much N do I need

Depends on the yearDepends on the year

Favorable growing conditionsFavorable growing conditions More NMore N

Unfavorable growing conditionsUnfavorable growing conditions Get by with less NGet by with less N

MMaximum aximum RReturn eturn TTo o NN and and Most Profitable N Rate RangeMost Profitable N Rate Range

Iowa - SC

0

20

40

60

80

100

120

140

160

0 50 100 150 200 250

N Rate, lb N/acre

Retu

rn t

o N

, $/a

cre

0.050.100.150.20 HIGHMRTNLOW

$2.20/bu

$0.11/lb N

$0.22

$0.33

$0.44

MMaximum aximum RReturn eturn TTo o NN and and Most Profitable N Rate RangeMost Profitable N Rate Range

Iowa - CC

0

20

40

60

80

100

120

140

160

0 50 100 150 200 250

N Rate, lb N/acre

Ret

urn

to

N,

$/ac

re

0.050.100.150.20

http://extension.agron.iastate.edu/soilfertility/nrate.aspx

How much P do I needHow much P do I need

Look at soil sampling resultsLook at soil sampling results Try to stay in the optimum rangeTry to stay in the optimum range 11-20 ppm depending on subsoil amount11-20 ppm depending on subsoil amount

Crop removalCrop removal Corn –grain, silage, and/or stoverCorn –grain, silage, and/or stover SoybeansSoybeans

Nutrient Content of Nutrient Content of Harvested CropsHarvested Crops

lb per Unit of Yield

Crop Unit P2O5 K2O

Corn Bu 0.375 0.30

Corn Silage Ton 3.50 6.50

Soybean Bu 0.80 1.50

Alfalfa Ton 12.50 40.00

Pm-1688 General Guide for Crop Nutrient Recommendations in Iowa

Current Grain PCurrent Grain P22OO55 RemovalRemoval

Anywhere from 80-125# PAnywhere from 80-125# P22OO5 5 per rotationper rotation

CornCorn 150 bu 150 bu 56# P56# P22OO55

175 bu 175 bu 66# P66# P22OO55

200 bu 200 bu 75# P75# P22OO55

SoybeansSoybeans 40 bu 40 bu 32# P32# P22OO55

50 bu 50 bu 40# P40# P22OO55

60 bu 60 bu 48# P48# P22OO55

Long-Term Benefits From Agronomic Long-Term Benefits From Agronomic Application of Manure To Crop LandApplication of Manure To Crop Land

Improved productivityImproved productivity Improved fertilityImproved fertility

Essential plant nutrientsEssential plant nutrients Adds organic matterAdds organic matter Stimulates biological activityStimulates biological activity

Improves physical structureImproves physical structure InfiltrationInfiltration StabilityStability Water holding capacityWater holding capacity Bulk densityBulk density

Nutrients in manure should be Nutrients in manure should be managed with the same care as managed with the same care as commercial fertilizercommercial fertilizer

We have to determine:We have to determine: Amount of nutrients in the manureAmount of nutrients in the manure

Availability of the nutrients to the cropAvailability of the nutrients to the crop

Amount of nutrients needed to optimize crop yieldsAmount of nutrients needed to optimize crop yields

That manure is being applied uniformlyThat manure is being applied uniformly

Determining the Nutrient Determining the Nutrient Content of ManureContent of Manure

Have a certified lab test the manureHave a certified lab test the manure

Having a chemical analysis Having a chemical analysis Needs to be done from representative Needs to be done from representative

sample of manuresample of manure Eliminates the question of what might be the Eliminates the question of what might be the

nutrient content of the manurenutrient content of the manure

Plant availability of the Plant availability of the nutrients in animal manurenutrients in animal manure

Animal manure contains all the nutrients Animal manure contains all the nutrients essential for plant growth.essential for plant growth.

The nutrients are present in both organic and The nutrients are present in both organic and inorganic forms.inorganic forms. The nutrients in inorganic form are readily available.The nutrients in inorganic form are readily available. The nutrients in organic form must be converted into The nutrients in organic form must be converted into

inorganic form. This conversion, mineralizationinorganic form. This conversion, mineralization ,, is is accomplished by microorganisms that live in all soilsaccomplished by microorganisms that live in all soils

Availability of nitrogen in Availability of nitrogen in animal manureanimal manure

Nitrogen is present in both organic and Nitrogen is present in both organic and inorganic forms in animal manure.inorganic forms in animal manure. The total amount of N present and the The total amount of N present and the

proportion of organic to inorganic N depends on proportion of organic to inorganic N depends on animal species and how the manure is handled animal species and how the manure is handled and stored.and stored.

Recent research suggests:Recent research suggests: About About 35%35% of the total N in dry cattle and dairy of the total N in dry cattle and dairy

manure is available to plants the year of manure is available to plants the year of applicationapplication

Nitrogen lossNitrogen loss

The two forms of inorganic N in animal manure are The two forms of inorganic N in animal manure are ammonium (NHammonium (NH44

++) and urea.) and urea.

If manure is left on the soil’s surface, ammonium If manure is left on the soil’s surface, ammonium and urea will form ammonia gas and be lost to the and urea will form ammonia gas and be lost to the atmosphere (atmosphere (volatilization)volatilization)..

You must make adjustments for volatilization You must make adjustments for volatilization losses of N.losses of N.

Use correction factors to account Use correction factors to account for nitrogen volatilization during for nitrogen volatilization during land application of animal manureland application of animal manure

Correction factors to account for N volatilization during land Correction factors to account for N volatilization during land application of animal manures.application of animal manures.

Application MethodApplication Method Correction FactorCorrection Factor

Direct injectionDirect injection 0.98 0.98 Bdcst & incorp. w/in 24 hrsBdcst & incorp. w/in 24 hrs 0.95 0.95 Bdcst & incorp. after 24 hrsBdcst & incorp. after 24 hrs 0.80 0.80 Bdsct liquid, no incorp.Bdsct liquid, no incorp. 0.75 0.75 Bdcst dry, no incorp.Bdcst dry, no incorp. 0.70 0.70 Irrigation, no incorp. 0.60Irrigation, no incorp. 0.60

Source: Iowa Department of Natural ResourcesSource: Iowa Department of Natural Resources

Availability of phosphorus Availability of phosphorus in animal manurein animal manure

P is present in both inorganic and organic P is present in both inorganic and organic forms.forms.

If the soil test for P is “high” or “very high” If the soil test for P is “high” or “very high” consider that consider that 100%100% of the P is available. of the P is available.

If the soil test for P is “very low,” “low,” or If the soil test for P is “very low,” “low,” or “optimum” consider that “optimum” consider that 60%60% of the total of the total P will be available the year of application.P will be available the year of application.

To determine a rate what To determine a rate what nutrient do I use?nutrient do I use?

Manure application rates can be Manure application rates can be determined using either N, P, or K needs.determined using either N, P, or K needs.

Depending on which set of regulations Depending on which set of regulations

you fall under, and P index value.you fall under, and P index value.

N and P are used most frequently to N and P are used most frequently to determine application rates.determine application rates.

Example of determining a Example of determining a RateRate

You have solid manure from a beef operation that contains 12 You have solid manure from a beef operation that contains 12 lb N, 6 lb Plb N, 6 lb P22OO55, and 12 lb K, and 12 lb K22O per ton.O per ton.

You have established that you can grow 175 bushels of corn per acre You have established that you can grow 175 bushels of corn per acre on a field in southwest Iowa. Last year’s soybean crop yielded 50 on a field in southwest Iowa. Last year’s soybean crop yielded 50 bushels/acre.bushels/acre.

N fertilizer = (175 x 1.2) - 50 lb N/acreN fertilizer = (175 x 1.2) - 50 lb N/acre = 210 - 50 = 160 lb N/acre= 210 - 50 = 160 lb N/acre

Manure rate = 160 lb N/acre Manure rate = 160 lb N/acre 2.9 lb N per ton 2.9 lb N per ton= 55 tons/acre= 55 tons/acre

But did we over apply PBut did we over apply P [[55 tons x 6 lb P55 tons x 6 lb P22OO55/ton = 330 lb P/ton = 330 lb P22OO55/acre/acre]]

Example of determining a Example of determining a Rate (Problem)Rate (Problem)

You have solid manure from a beef operation You have solid manure from a beef operation that contains 12 lb N, 6 lb Pthat contains 12 lb N, 6 lb P22OO55, and 12 lb K, and 12 lb K22O O

per ton.per ton.

But did we over apply PBut did we over apply P

[[55 tons x 6 lb P55 tons x 6 lb P22OO55/ton = /ton = 330 lb P330 lb P22OO55/acre/acre]]

According to your P index can you apply according According to your P index can you apply according to N requirements or P?to N requirements or P?

Tons of Manure vs. Tons of Manure vs. Nutrient NeedNutrient Need

Crop Nutrients from Cattle Feedlot Manure with Rate

Based on Total N Application

Nutrient Removal in Grain Based on 50 bu/acre Soybean and 175

bu/acre Corn Yields

Manure Application, tons/acre S-C

Nutrient 10 18 55 Soybean Corn Rotation

- - - - - - - - lb/acre - - - - - - - - - - - - - - - - - lb/acre - - - - - - - -

N 29 52 160 0 160(?) 160

P2O5 60 108 330 40 66 106

K2O 120 216 660 75 40 115 Example manure nutrient values for beef feedlot finishing, confined unit: 12 lb total N/ton; 6 lb P2O5/ton; 12 lb K2O/ton. N available calculated at 2.9#/ton. About 11 tons per head per year are produced, according to ISU Publication ICM – 1.

Concerns with DDGSConcerns with DDGS

From Table 2, “Use of Distillers Grain in From Table 2, “Use of Distillers Grain in Feedlot Diets”Feedlot Diets” 15% DDGS in diet increases excreted P15% DDGS in diet increases excreted P22OO55 by 20% by 20% 25% increases excreted by 40%25% increases excreted by 40% 40% increase by 70%40% increase by 70%

Additional Concern regarding ApplicationAdditional Concern regarding ApplicationDry manure spreaders are not calibrated often enoughDry manure spreaders are not calibrated often enoughDry spreaders aren’t always very uniform in Dry spreaders aren’t always very uniform in

application.application.

Manure Application: Manure Application: things to think aboutthings to think about

Fall applications allow time for organic portions of the Fall applications allow time for organic portions of the manure to mineralize.manure to mineralize.

Fall applications also allow for more potential N loss to Fall applications also allow for more potential N loss to the environment.the environment.

To conserve N that is in the manure from loss To conserve N that is in the manure from loss Apply manure in the fall when the soil temperature (4” deep in Apply manure in the fall when the soil temperature (4” deep in

the soil) is 50the soil) is 50o o F and cooling.F and cooling. Applying manure to frozen soils increases the potential Applying manure to frozen soils increases the potential

for environmental contamination.for environmental contamination. N and P movement into surface water can be significant.N and P movement into surface water can be significant. Apply only on relatively flat land (slopes of 4 % or less).Apply only on relatively flat land (slopes of 4 % or less).

A little common sense will keep problems awayA little common sense will keep problems away

Feeding DDGS, How am I going Feeding DDGS, How am I going to change to accommodate to change to accommodate higher manure Phigher manure P

Applying manure with higher P contentApplying manure with higher P content Crop removalCrop removal Soil test resultsSoil test results Manure test resultsManure test results

Higher P manure if applied by P requirements:Higher P manure if applied by P requirements: Larger number of acres to applyLarger number of acres to apply Different/Better equipment to get to these acres? Different/Better equipment to get to these acres?

(may be further away)(may be further away) More acres=more timeMore acres=more time

SummarySummary

Commercial fertilizer costs $Commercial fertilizer costs $ $400 anhydrous 1#N is $0.24$400 anhydrous 1#N is $0.24 $340 11-52-0 1# P$340 11-52-0 1# P22OO5 5 is $0.33is $0.33 $255 0-0-60 1# K$255 0-0-60 1# K22O is $0.21O is $0.21

What your manure is worth in terms of nutrients and organic What your manure is worth in terms of nutrients and organic matter = increased biological activity, better soil structure, matter = increased biological activity, better soil structure, increased infiltration, increased water holding capacity, increased increased infiltration, increased water holding capacity, increased pH buffering capacitypH buffering capacity

Corn - Corn rotations will need more N and P than a traditional Corn - Corn rotations will need more N and P than a traditional Corn - Soybean rotationCorn - Soybean rotation

Use your resource and take credit for itUse your resource and take credit for it

Questions-comments?Questions-comments?