Manure and compost are important sources of nitrogen for organic producers. Determining the actual amount of nitrogen available for plant use is a challenging obstacle for producers. A nutrient management plan needs to consider the following factors when determining nitrogen recommendations for crop needs.
Source Influence of Manure and Compost
Manure and compost nitrogen content and availability can vary greatly between species of animals that produced the manure. Table 1 compares the nitrogen content availability for different poultry. Poultry manure typically has the highest nitrogen content. Laboratory analysis is recommended to determine actual nitrogen content of the source material.
Table 1. Actual Analysis of Inputs Measured at OSU Hirzel Organic Grain Research Site | |||||
Nitrogen Source
|
Analysis total N
|
Moisture
|
Total N lbs/ton
|
Typical rate per acre
|
Total N per acre
|
Straw pack beef manure
|
0.96 %
|
73 %
|
19.1
|
4 ton
|
76.4 lb
|
Leaf, cannery, horse, duck compost
|
0.8 %
|
36 %
|
16.0
|
4 ton
|
64.0 lb
|
Leaf, cannery, horse, duck compost
|
0.89 %
|
32 %
|
17.8
|
4 ton
|
71.2 lb
|
Leaf, cannery, horse, duck compost
|
1.01 %
|
51 %
|
20.2
|
4 ton
|
80.8 lb
|
Poultry compost
|
1.75 %
|
24 %
|
35.0
|
2 ton
|
70.0 lb
|
Poultry compost
|
2.01 %
|
20 %
|
40.2
|
2 ton
|
80.4 lb
|
Poultry compost
|
2.5 %
|
35 %
|
50.0
|
2 ton
|
100.0 lb
|
Poultry compost
|
4.0 %
|
|
80.0
|
2 ton
|
160.0 lb
|
Bedding or Additives
In the case of manure, the amount and type of bedding added to the manure will influence the nitrogen content and availability. In the same manner, the type of additives used to create the compost will influence compost nitrogen content. Components such as leaves, corn stalks, straw, wood chips or other organic materials vary greatly in the amount and availability of their nitrogen content. The uniformity of the material is also important, especially in straw pack manure where animal patterns in the barn determine concentrations of raw manure. Accurate sampling with representative source materials will result in more accurate analysis.
Moisture
The amount of liquid contained in the manure or compost affects the concentration of nitrogen per ton applied. Table 2 illustrates the nitrogen differences between raw manure and manure with bedding.
Table 2. Estimated Nitrogen Content of Various Manures | |||
Animal Type | Raw manure >75% moisture | Manure pack with bedding | |
N lbs/ton | N lbs/ton | ||
Dairy | 5.3 – 9.8 | 4.2 – 6.9 | |
Beef | 7.4 – 10.6 | 7.9 | |
Swine | 10.4 – 12.6 | 6.6 | |
Sheep | 15.0 | 6.3 | |
Poultry | 19.2 – 21.0 | 52.0 dry | |
Horse | 7.4 | 6.6 | |
These values include a 25% loss factored due to storage and handling losses prior to land application. Source: Ohio Livestock Manure Management Guide, Ohio State University Bulletin 604. |
Storage and Handling Losses
As manure and compost are stored over time, nitrogen losses may occur due to exposure to the atmosphere. Producers need to account for these losses of nitrogen over time. Losses also occur when moving manure or compost before field applications. Typically a factor of 25 percent loss is used.
Application Rate
Knowing the amount of material applied per acre will help achieve intended supplies of nitrogen for the target crop. Accurate interpretation of laboratory analysis is needed to calculate the target application rate. Calibration of spreaders improves accuracy of application rates. The capacity of the spreader needs to be determined. This can be done by weighing an average load of manure. Then the number of spreader loads per field can be calculated (Mancl, 1991). Nitrogen application rates must also consider other nutrients applied, such as phosphorus, to prevent excessive soil nutrient levels.
Volatilization Losses
Immediate incorporation or injection of manure or compost minimizes losses of ammonium nitrogen to the atmosphere. Under warm and dry soil conditions, up to 90 percent of ammonium could be lost due to volatilization without incorporation. Delaying incorporation by one day under these conditions could result in an additional 50 percent loss. Compost is a more stable material and will have less volatilization losses compared to manures. Table 3 identifies the nitrogen losses expected, based on weather conditions, incorporation timing and field moisture.
Table 3. Ammonia Nitrogen Losses from Volatilization from Manure | |||||
Incorporation Delay from Application | Residue Coverage | Cool Temperature | Warm Temperature | ||
Wet Soil | Dry Soil | Wet Soil | Dry Soil | ||
Ammonia Loss, % applied | |||||
No Incorporation | Bare Soil | 40 | 50 | 75 | 90 |
No Incorporation | Standing Crop | 20 | 25 | 40 | 50 |
1 day | Bare Soil | 10 | 15 | 25 | 50 |
2 day | Bare Soil | 13 | 19 | 31 | 57 |
3 day | Bare Soil | 15 | 22 | 38 | 65 |
4 day | Bare Soil | 17 | 26 | 44 | 73 |
Natural Resource Agriculture and Engineering Service (NRAES) 130 |
Plant Available Nitrogen
Not all the nitrogen applied as manure or compost is immediately available to the crop, as shown in Table 1. Residual nitrogen may be released over several years in the soil. Calculating plant available nitrogen is influenced by the source, timing of application, soil conditions and temperature. First year available organic nitrogen is estimated at 33 percent and ammonium nitrogen available first year can range from 15 to 75 percent depending on application timing.
Organic producers need to have an understanding of plant available nitrogen derived from compost or manure sources. Cereal grain crops such as corn, wheat, oats and spelt need this available nitrogen to produce grain. By compensating for potential losses, satisfactory crop yields in organic production may still be achieved.
Acknowledgments
- Funding to support the management of the Hirzel site and the development of these materials was provided by Ohio Agricultural Research and Development Center (OARDC) Organic Food, Farming, Education and Research Program at oardc.osu.edu/offer.
- This publication was produced in cooperation with Ohio State University’s John E. Hirzel Sustainable Agriculture Research and Education Site and the Agricultural Incubator Foundation at Bowling Green, Ohio.
- The author dedicates this publication in memory of John Hirzel, long-time supporter of sustainable agriculture, state leader in organic grain and vegetable production, and friend.
Bibliography
- James, R., et al. (2006). Ohio Livestock Manure Management Guide, 2006. Ohio State University Extension Bulletin 604.
- Meisinger, J. & Jokela, W. (2000). Ammonia Volatilization from Dairy and Poultry Manure. Adapted from (NRAES-130) Natural Resource Agriculture and Engineering Service, Box 4557, Ithaca, NY. 14852. Retrieved on March 25, 2014 from
dairyn.cornell.edu/pages/20cropsoil/documents/MeisingerandJokela-NRAES130-2000.pdf - Mancl, K. (1991). Land Application of Waste: Spreading and Injection. Ohio State University Extension Factsheet AEX-707-91.
- Smith, R. (2006). Nitrogen Fertility Management in Organic Production, University of California Extension presentation. Retrieved on March 25, 2014 from
cemonterey.ucanr.edu/files/85316.pdf - Sullivan, D. (2008). Estimating Plant-available Nitrogen from Manure. Oregon State University Extension Bulletin EM 8954 E. Retrieved on March 8, 2024 from
researchgate.net/publication/346060031_Estimating_Plant-available_Nitrogen_from_Manure