Nitrogen Loss—Spring 2013

Dry soils across Iowa from deficit precipitation following the drought in 2012 have changed to excess wetness this spring. Unfortunately, precipitation to replenish subsoil moisture has been much more than needed. As I wrote in an ICM News article earlier this spring, one downside to the excess precipitation has been movement of carryover nitrate deeper into the profile and to tile lines, resulting in high nitrate-N concentrations in surface waters. This means there is less nitrate-N carryover to be utilized by 2013 crops, although as noted in the previous article, not all of the carryover N moved below the three-foot depth