1. Corn Yield Response to Fall and Spring Applied Controlled- Release Urea vs. Spring Conventional Urea

Nitrogen (N) application to corn has been proven to increase yields, but concerns about nitrate-N in ground and surface water have led to investigation of controlled-release N fertilizer. The objective of these experiments is to compare corn grain response to controlled-release urea (ESN) and conventional urea. Two field studies are being conducted at two locations in Iowa and corn yield data will be reported from 2003-2005. All N treatments were hand broadcast in 30 lb N/a increments from 0 lbs....