If you take care of the nitrogen needs, you will have more than enough phosphorus. The nitrogen and phosphorus content of manure varies greatly between animal species and how manure is handled and stored. A manure test, like a soil test, is highly recommended to determine the proper rate to adequately replace fertilizer and to prevent nutrient losses to the environment. Ask your county Extension educator for information on soil and manure sampling and analysis. Gerwing added that a bonus for using manure comes from increased microbial activity it creates in soils.
Soil microbes feed on the organic material and nutrients in manure.
The increased organic material and enhanced microbial activity creates soil with better structure, water-holding capacity and rooting environment for plants, all of which help increase yields, Gerwing said. In some areas farmers have recognized the economic value of manure as nitrogen fertilizer replacement and are actually paying their neighbors for part of the value, Gerwing said.