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Spreading Poultry Litter With Lab Analysis and With Soil Tests

Charles D. Fulhage and Donald L. Pfost
Department of Agricultural Engineering

Editor's note
The printed version of this publication includes illustrations.

A primary need and concern for most poultry producers is managing litter. You must protect ground and surface water and fulfill regulatory requirements. Usually, the goals are met by applying litter to the land in a way that uses potentially polluting nutrients, such as nitrogen (N), phosphorus (P), potash (K2O) and organic matter.

Litter as a fertilizer

View litter as a fertilizer resource and manage it like commercial fertilizer in your fertility program. You can damage water quality by meeting fertility requirements with commercial fertilizer then applying litter for good measure.

Missouri waste application regulations are based on the rate of nitrogen applied. With this plan, the phosphate (P2O5) and potash applied may exceed crop needs greatly.

The best fertility plan may apply less nitrogen from waste than the crop needs and buy supplemental nitrogen to balance the fertility program. Applying phosphorus to fields with a Bray 1-P test level of more than 800 pounds per acre may aggravate surface water quality problems.

It is highly recommended that you analyze a representative sample of poultry litter for nutrient values immediately before spreading. The analysis, in addition to soil tests, determines the land application rate.

This publication provides guidance for application of waste with the benefit of a lab analysis and a soil test. Other publications in this series address application of dairy waste with other plans.

Managing litter as a fertilizer

Unlike commercial fertilizers, poultry litter is a highly variable substance. Even within a given animal specie, waste can vary up to 50 percent. Other management styles peculiar to poultry operations, such as building cleaning on a certain schedule, dictate a different management technique than commercial fertilizer that can just be ordered and spread.

In contrast to commercial fertilizer, litter has the potential for nutrients (primarily ammonia nitrogen) to be lost to the atmosphere after field spreading. Table 1 shows the available ammonia nitrogen as a function of time until incorporated into the soil.

Table 1
Litter ammonia nitrogen loss by days until incorporated into the soil. Unavailable portion is lost to the atmosphere

Days until incorporation Percent of ammonia N available for crops
0 to 2 80
2 to 4 60
4 to 7 40
more than 7 20

Table 2 lists the percent of available organic nitrogen available by year. Table 3 gives the percent of various nutrients available in the growing season after application.

Table 2
Litter organic nitrogen available by year

Manure applied Percent of organic N available during current year
Current year 40 to 60
One year ago 10
Two years ago 5
Three years ago 5

Table 3
Other minerals and micronutrients available in litter

Nutrient Percent of ammonia N available in growing season
P 80
K 100
S, Mn, Cu, Zn 80
Ca, Mg 100

Table 4
Lab analysis for litter and rate of past applications

Nutrient Nutrient content of broiler litter (pounds per ton)
This year 1 year ago 2 years ago 3 years ago
Total N 64 52.0 69.0 71.0
NH4-N 10 9.0 15.0 18.0
Organic N 54 43.0 54.0 53.0
P2O5 60 44.0 63.0 68.0
K2O 40 33.0 40.0 45.0
Tons per acre applied ? 2.5 2.0 2.0

This publication details a procedure for calculating the amount of litter to apply to meet the soil test recommendations for nitrogen using a poultry litter of known nutrient analysis. The soil test may call for more than 100 pounds of nitrogen per acre to be added to satisfy crop needs. This exceeds the 100 pounds per acre allowed under the conservative management approach.

However, you may wish to use this worksheet with the conservative approach of applying 100 pounds of N to see what happens with P and K.

Blank worksheets are included for actual applications.

This approach cannot be used if the Department of Natural Resources has issued a letter of approval based on the conservative approach of applying not more than 100 pounds of nitrogen per year, regardless of the crop and the production level of the crop.

Example 1

A fescue hay field soil/plant filter is available for receiving broiler litter. The accompanying soil test contains fertilizer recommendations for a yield goal of 3 tons of fescue hay per year from the soil/plant filter area.

From the soil test, the following nutrient applications are recommended:

  • 120 pounds N per acre
  • 75 pounds P2O5 per acre
  • 140 pounds K2O per acre

Given this information and the laboratory analysis of the broiler litter (Table 4), how many tons per acre of broiler litter should be applied to meet the nitrogen needs of the fescue?

Litter has been applied the past three years with the rates and analyses noted in Table 4. The litter applied will not be incorporated into the soil. Ammonia nitrogen loss is 80 percent.

Worksheet 1
Broiler litter on fescue

  1. Crop nutrient requirements (from soil test)
    "Fescue"
    Yield "3" tons per acre
    Nitrogen "120" pounds per acre
    P2O5 "75" pounds per acre
    K2O "140" pounds per acre
  2. Available ammonia nitrogen (NH4-N)
    NH4-N pound per ton x percent available = NH4-N pound per ton (Percent from Table 1, NH4-N from Table 4)
    "10" pounds per ton x "0.2" percent available = "2" pounds per ton
  3. Nitrogen available from this year's organic fraction
    N pounds per ton x percent available = N pounds per ton (Percent from Table 2, organic N from Table 4)
    "54" pounds per ton x "0.5" percent available = "27" pounds per ton
  4. Residual nitrogen available from past years' organic fraction
    Tons per acre x N pounds per ton x percent available = N pounds per acre (Percent from Table 2, organic N from Table 4)
    1 year ago "2.5" tons per acre x "43" pounds per ton x "0.10" percent available = "10.8" pounds per acre
    2 years ago "2.0" tons per acre x 54 pounds per ton x "0.05" percent available = "5.4" pounds per acre
    3 years ago "2.0" tons per acre x 53 pounds per ton x "0.05" percent available = "5.3" pounds per acre
    Total = "21.5" pounds per acre
  5. Manure application rate to supply nitrogen
    (Crop N (line 1)) - (residual N (line 4))
    _____________________
    (Available NH4-N (line 2)) + (available organic nitrogen (line 3))
    = application rate tons per acre
    120 - 21.5
    _____________________
    2 + 27
    = 3.4 tons per acre
  6. Phosphate available at calculated application rate for nitrogen
    Tons per acre x P2O5 pounds per ton x percent available = P2O5 pounds per acre (P2O5 per ton from Table 4, percent from Table 3)
    "3.4" tons per acre x "60" pounds per ton x "0.8" percent available = "163*" pounds per acre

*Note
163 pounds per acre P2O5 is applied vs. 75 pounds per acre recommended by soil test.

  1. Potash available at calculated application rate for nitrogen
    Tons per acre x K2O pounds per ton x percent available = K2O pounds per acre (K2O per ton from Table 4, percent from Table 3)
    "3.4" tons per acre x "40" pounds per ton x "1" percent available = "136*" pounds per acre

*Note
136 pounds per acre K2O is applied vs. 140 pounds per acre recommended by soil test.

Example 2

The information is the same as Example 1, except no litter was applied the past three years. Use only the information for this year (Table 4).

Worksheet 2
Broiler litter on fescue with no litter applied past three years

  1. Crop nutrient requirements (from soil test)
    "Fescue"
    Yield "3" tons per acre
    Nitrogen "120" pounds per acre
    P2O5 "75" pounds per acre
    K2O "140" pounds per acre
  2. Available ammonia nitrogen (NH4-N)
    NH4-N pounds per ton x percent available = NH4-N pounds per ton (Percent from Table 1, NH4-N from Table 4)
    "10" pounds per ton x "0.2" percent available = "2" pounds per ton
  3. Nitrogen available from this year's organic fraction
    N pounds per ton x percent available = N pounds per ton (Percent from Table 2, organic N from Table 4)
    "54" pounds per ton x "0.5" percent available = "27" pounds per ton
  4. Residual nitrogen available from past years' organic fraction
    No litter applied the past three years.
  5. Manure application rate to supply nitrogen
    (Crop N (line 1)) - (residual N (line 4))
    _____________________
    (Available NH4-N (line 2)) + (available organic nitrogen (line 3))
    = application rate tons per acre
    120 - 0
    _____________________
    2 + 27
    = 4.1 tons per acre
  6. Phosphate available at calculated application rate for nitrogen
    Tons per acre x P2O5 pounds per ton x percent available = P2O5 pounds per acre (P2O5 per ton from Table 4, percent from Table 3)
    "4.1" tons per acre x "60" pounds per ton x "0.8" percent available = "196.8*" pounds per acre

*Note
196.8 pounds per acre P2O5 is applied vs. 75 pounds per acre recommended by the soil test.

  1. Potash available at calculated application rate for nitrogen
    Tons per acre x K2O pounds per ton x percent available = K2O pounds per acre (K2O per ton from Table 4, percent from Table 3)
    "4.1" tons per acre x "40" pounds per ton x "1" percent available = "164*" pounds per acre

*Note
164 pounds per acre K2O is applied vs. 140 pounds per acre recommended by the soil test.

Example 3

Broiler litter is spread on corn ground, according to the soil test and the lab analysis of the litter (Table 4). The litter is not incorporated into the soil within seven days. Ammonia nitrogen loss is 80 percent. Litter was spread on the area the past three years at the rates listed in Table 4. The yield goal for corn is 160 bushels per acre. Nutrient requirements are noted in the soil test for corn. A previous soybean (legume) crop provides a 30 pound per acre nitrogen credit as noted on the soil test sheet.

Worksheet 3
Broiler litter on corn

  1. Crop nutrient requirements (from soil test)
    "Corn"
    Yield "160" tons per acre
    Nitrogen "160*" pounds per acre
    P2O5 "95" pounds per acre
    K2O "96" pounds per acre

*Note
Since soybeans were the last crop, N = 190 - 30 = 160 pounds per acre

  1. Available ammonia nitrogen (NH4-N)
    NH4-N pounds per ton x percent available = NH4-N pounds per ton (Percent from Table 1, NH4-N from Table 4)
    "10" pounds per ton x "0.2" percent available = "2" pounds per ton
  2. Nitrogen available from this year's organic fraction
    N pounds per ton x percent available = N pounds per ton (Percent from Table 2, organic N from Table 4)
    "54" pounds per ton x "0.5" percent available = "27" pounds per ton
  3. Residual nitrogen available from past years' organic fraction
    Tons per acre x N pounds per ton x percent available = N pounds per acre (Percent from Table 2, organic N from Table 4)
    1 year ago "2.5" tons per acre x "43" pounds per ton x "0.10" percent available = "10.8" pounds per acre
    2 years ago "2.0" tons per acre x "54" pounds per ton x "0.05" percent available = "5.4" pounds per acre
    3 years ago "2.0" tons per acre x "53" pounds per ton x "0.05" percent available = "5.3" pounds per acre
    Total = "21.5" pounds per acre
  4. Manure application rate to supply nitrogen
    (Crop N (line 1)) - (residual N (line 4))
    _____________________
    (Available NH4-N (line 2)) + (available nitrogen (line 3))
    = application rate tons per acre
    160 - 21.5
    _____________________
    2 + 27
    = 4.8 tons per acre
  5. Phosphate available at calculated application rate for nitrogen
    Tons per acre x P2O5 pounds per ton x percent available = P2O5 pounds per acre (P2O5 per ton from Table 4, percent from Table 3)
    "4.8" tons per acre x "60" pounds per ton x "0.8" percent available = "230*" pounds per acre

*Note
230 pounds per acre of P2O5 is applied vs. 95 pounds per acre recommended by the soil test.

  1. Potash available at calculated application rate for nitrogen
    Tons per acre x K2O pounds per ton x percent available = K2O pounds per acre (K2O per ton from Table 4, percent from Table 3)
    "4.8" tons per acre x "40" pounds per ton x "1" percent available = "192*" pounds per acre

*Note
192 pounds per acre of K2O is applied vs. 95 pounds per acre recommended by the soil test.

Worksheet 4
Litter fertility worksheet

  1. Crop nutrient requirements (from soil test)

    Yield tons per acre
    Nitrogen pounds per acre
    P2O5 pounds per acre
    K2O pounds per acre
  2. Available ammonia nitrogen (NH4-N)
    NH4-N pound per ton x percent available = NH4-N pound per ton (Percent from Table 1, NH4-N from lab test)
    pounds per ton x percent available = pounds per ton
  3. Nitrogen available from this year's organic fraction
    N pounds per ton x percent available = N pounds per ton (Percent from Table 2, organic N from lab test)
    pounds per ton x percent available = pounds per ton
  4. Residual nitrogen available from past year's organic fraction
    Tons per acre x N pounds per ton x percent available = N pounds per acre (Percent from Table 2, organic N from lab test)
    1 year ago: tons per acre x pounds per ton x percent available = pounds per acre
    2 years ago: tons per acre x pounds per ton x percent available = pounds per acre
    3 years ago: tons per acre x pounds per ton x percent available = pounds per acre
    Total = pounds per acre
  5. Manure application rate to supply nitrogen
    (Crop N requirement (line 1)) - (residual N (line 4))
    _____________________
    (Available NH4-N (line 2)) + (available organic nitrogen (line 3))
    = application rate tons per acre
    ______ - ______
    _____________________
    ______ + ______
    = tons per acre
  6. Phosphate available at calculated application rate for nitrogen
    Tons per acre x P2O5 pound per ton x percent available = P2O5 pounds per acre (Percent from Table 3)
    Tons per acre x pounds per ton x percent available = pounds per acre
  7. Potash available at calculated application rate for nitrogen
    Tons per acre x K2O pound per ton x percent available = K2O pounds per acre (Percent from Table 3)
    Tons per acre x pounds per ton x percent available = pounds per acre

 


WQ223 Spreading Poultry Litter With Lab Analysis and With Soil Tests | University of Missouri Extension