254-1 Estimating Nitrogen Mineralization In Indiana Soils.



Tuesday, October 18, 2011: 1:05 PM
Henry Gonzalez Convention Center, Room 216A, Concourse Level

Chun Zhao, Purdue University, West Lafayette, IN, James Camberato, Agronomy, Purdue University, West Lafayette, IN and Brad Joern, Agronomy, Purdue University, W. Lafayette, IN
Previous field research in Indiana found soil N supply was the most important factor determining fertilizer N rate needed to optimize corn yield. However, current soil testing methods do not predict soil N supplying capacity, which limits our ability to develop more accurate N fertilizer recommendations. The objectives of this study were to (1) determine the mineralizable N in major soil types of Indiana that differed substantially in organic matter, texture, and previous crop; (2) compare laboratory and greenhouse N mineralization estimates to field measurements of N supplying capacity. We assessed N mineralization in the soils with two incubation procedures - leaching tube incubation and static cup incubation. Total N uptake by wheat grown in the greenhouse was also measured to determine soil N supplying capacity under greenhouse conditions. The results showed soil N mineralization rates varied among different soils but were not correlated to soil organic matter content (p=0.18). Additionally, although the mineralized N in the laboratory incubation was consistent with greenhouse mineralization, it did not predict the field N supplying capacity.
See more from this Division: S04 Soil Fertility & Plant Nutrition
See more from this Session: Nitrogen and Crop Production: I