As the time to start planning spring plantings, farmers must consider what types of fertilizers to use. Many farmers have an abundance of animal waste at their fingertips, and considering the prices of commercial fertilizers, they would be wise to weigh those alternative options.
According to Thomas Hansen, a University of Missouri Extension agronomy specialist, animal manures do contain all the nutrients a plant needs to grow, but they don’t necessarily contain the quantities needed.
“The quantity and ratio of nutrients of the different manures depends a great deal on what the animals are fed,” Hansen said.
In northwest Arkansas and southwest Missouri, poultry litter – broiler or turkey waste – is more prevalent than waste from cattle.
There are several factors to consider when applying poultry litter as fertilizer. First, Hansen recommends a soil test to indicate the levels of phosphorus and potassium needed in the soil. Hansen said he has seen nitrogen and phosphorus values range from about 20 pounds per ton to over 100 pounds per ton. Soil testing makes it easy to analyze what deficiencies the soil has and start from there.
Litter should be applied close to planting time, and, according to the University of Arkansas Cooperative Extension Service Web site, "it should be stored for short periods, in amounts that supply the needs of the current growing season. Storing litter for longer periods may reduce the material’s nutrient value and increase environmental risk and liability, especially if the material is not covered, as a portion of the nutrients could be lost by runoff.”
Mike Daniels, professor of water quality at the University of Arkansas, recommends that animal applications to pastures and crops be done following a nutrient management plan that has been written by a state-certified planner.
“A certified nutrient management plan will provide the appropriate application rate as well as any nutrient deficiencies that exist and how much commercial fertilizer would be needed if such a deficiency does exist,” Daniels said.
If farmers are interested in selling poultry waste, Daniels recommends they keep records of how much fertilizer they sold and of those to whom they sold it. They should keep the records for five years.
To determine the value of poultry litter, Hansen recommends multiplying the nutrients by the fertilizer cost per nutrient.
To properly use poultry litter The University of Arkansas Cooperative Extension Services offers these seven steps:
1. Take a representative soil sample to know how much P (P2O5) fertilizer is needed.
2. Obtain a chemical analysis of the litter.
3. Calculate the amount of litter needed to supply the amount of P2O5 required by your crop.
4. Calculate the amount of supplemental nutrients (i.e., N and K) needed.
5. Apply litter as close to planting as possible.
6. Incorporate the litter, if possible.
7. Take soil samples regularly to monitor buildup of nutrients in the soil.