Nitrogen watch for poorly- and somewhat poorly-drained soils


total precipitation Midwest

credit for MRCC maps

Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive.  My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30.  This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.