While most of Iowa has not been excessively wet this spring, a few areas have been hit with heavy rains. The potential for nitrogen (N) losses are low, but some fields or field areas are more at risk. Generally, losses should be minimized because wet soils occurred early in the spring when temperatures were cool and much of the heavy rainfall ran off fields. Of course, losses could change if we receive excessive rainfall into June, as occurred last year. If you are wondering about available N for this year's corn crop, you can consider a few methods to check the N status.
Available at: http://works.bepress.com/john-sawyer/29/