It is important to distinguish between uptake, or use by the growing crop, and removal, or the physical displacement of the nutrients from the field in the harvest. Determine the plant-available nutrients in broiler litter or other organic amendments. The best method is to sample the manures to be used on the field. Instructions on sampling and analysis of animal manures are available from the local Extension office or from sources listed below. Estimate residual nutrient contributions from fertilizer or manures applied in previous seasons.
Manures are the original slow-release nitrogen fertilizer.
Subsequent use is usually a sliding scale. The NRCS NMP Field Office Technical Guide has one such scale for use. It is clear that NMP uses the same inflow versus outflow as cash-flow analysis. Using Manure Use soil testing to assess fertility status. Determine nutrient and moisture content of the manure.