Search research reports:
Characterizing Active Soil Organic Matter Pools Controlling Soil N Availability in Maize-based Cropping Systems
Department of Plant and Soil Sciences
Predicting the supply of soil nitrogen to maize (corn) remains difficult, if not impossible. This project examines a number of new methodologies for assessing the various forms of soil nitrogen. The context of the work is short-term corn-N response trials on corn grower fields and long-term corn-N response trials on research farms. The ultimate purpose of the project is to come up with a valid soil test for soil nitrogen supply to maize (corn).
2009 Project Description
The most important objective of this work is to improve corn's nitrogen (N) use efficiency. The major research goal is to better understand the potential of split fertilizer N applications to increase corn's N use efficiency, across the USA. Field research was started in 2007, continued in 2008, and again in 2009, the third year of the study. Yields were significantly increased by split N application, largely because the season was much wetter than 2007 or 2008. The research information has been used to promote split N application, reduce total fertilizer N rates and lower the risk of environmental N loss. Output has taken the form of oral presentations to corn producers at meetings and field days.
The impact of the research results remains largely testimonial. No surveys documenting how KY corn producers provide N nutrition to the crop have been done. It is expected that the results will have broad impact in western Kentucky, especially with growers farming less than well-drained soils, causing a greater understanding of how N rate and timing drive corn-fertilizer N use efficiency. There is considerable controversy regarding the benefit, or lack thereof, to split/delayed N applications, especially on tile-drained soils.
Grove, J.H., E.M. Pena-Yewtukhiw, M. Diaz-Zorita and R.L. Blevins. 2009. Does fertilizer N burn up soil organic matter Better Crops With Plant Food 93(4):6-8.