Record: Batch number, each material with wet weight, assumed moisture and nitrogen, computed mix nitrogen, and what changed.
Write your last batch as weights of straw, manure, bran and gypsum.
Beside each, write the nitrogen per cent you assume and its source.
Work out the mix nitrogen on a dry weight basis.
Compare with 1.5 to 1.75 per cent and adjust one material.
File the sheet with the batch number for comparison.

