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36. Determine Accurate Manure Application Rates

manure storage

When applying manure to fields as fertilizer, accurate rates make sense from all angles—economic, agronomic, and environmental. Ensuring an accurate application rate involves determining the nutrient content of the manure on your farm, crop nutrient needs, and field application rates.

The preferred way to determine the nutrient content of livestock manure is to have it tested. The nutrient content can vary according to the storage system, animal diet, and various other factors. Therefore, collect a series of samples from each manure storage system or feedlot and have them analyzed annually.

corn field Determine crop nutrient needs on a field-by-field basis. The fertilizer recommendation for a field will depend on the crop to be grown, anticipated yield goal, previous crop, and soil test results.
applying manure to a field Once you have determined the nutrient content of manure and the nutrient needs of crops, calculate the application rate for each field. The rate can vary, depending on which nutrient you use as a basis for application.
applying manure to a field Manure is relatively high in phosphorus and low in nitrogen compared to most crops' needs for those nutrients. Therefore, from an economic, environmental, and agronomic perspective, it usually makes more sense to base your application rate on the P content of manure. This generally means you have to add supplemental nitrogen fertilizer, but doing so easily fits into most systems.

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