Nitrogen is released as ammonium- and nitrate-N from
organic matter in the soil through mineralization. Mineralization
is a microbial process that is favored by conditions favorable
to high corn yield; thus, the estimated credit for N from
organic matter is related to expected yield. When a soil test
for organic matter is not available, one percent organic matter
is assumed for sandy soils and soils in the Panhandle, and 2
percent is assumed for other soils. The maximum soil organic
matter content used in the algorithm is capped at 3 percent
organic matter since few Nebraska soils above this level were
represented in the database used to develop the equation.