Ammonia nitrogen is the form that is readily available to plants and is also subject to volatilization loss to the atmosphere if not immediately incorporated into the soil. Knowing both ammonia and organic nitrogen allows you to estimate the amount of nitrogen immediately available to plants, and the amount that will become available in later years as the organic nitrogen is released. Nitrogen may also be present in the nitrate form. However the highly anaerobic conditions existing in most livestock manure management systems usually preclude nitrate nitrogen except in trace amounts. However, since both are essentially immediately available to plants, it is not necessary to determine both forms, as it is with nitrogen.
Potassium has no organic fraction and is immediately available to plants.
Total-solids levels affect handling qualities and bulk density characteristics of manure. So, if a complete analysis is to be obtained, the laboratory should be instructed to run the following tests. If you are not sure what the capabilities of a laboratory are, call and ask. Micronutrients such as calcium, sodium and magnesium may be important in certain cases. These tests can usually be obtained at additional expense if the lab is so instructed.