Whole Farm Management Tutorials

Manure Analysis

Rapidly available N and more slowly released N appear in a standard manure analysis. The ammonium N on the manure analysis represents the "rapid N" (urine-N), while the organic N is equivalent to the "slow release N" (fecal-N). The lab determines total N by the Total Kjeldahl method and ammonium N by KCl extraction.  Organic N is then calculated by difference (i.e. total N - ammonium N = organic N).

In addition, analyses for phosphorus, potassium, total solids, and density are also included. Phosphorus and potassium are presented in both elemental form (i.e. P and K) and fertilizer industry form (i.e. P2O5 and K2O).  Use the following molecular weight conversions to switch between the two.

Nutrient concentration of the manure is often reported in three ways:

The remaining information on the manure analysis is a measurement of the total solids, otherwise known as the dry matter content of the manure, as well as the manure density.

To read more on this subject: Nitrogen Guidelines for Field Crops in New York (section 3.3)

The next section focuses on ammonium N in manure.

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