|Vories, Earl - Earl|
Submitted to: Nitrogen Workshop Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 4/15/2013
Publication Date: 4/15/2013
Citation: Tremblay, N., Bouroubi, M.Y., Belec, C., Mullen, R.L., Kitchen, N.R., Thomason, W.E., Ebelhar, S.A., Mengel, D.B., Raun, W.R., Francis, D.D., Vories, E.D., Ortiz-Monasterio 2013. A Meta-Analysis quantifying the relationships between response to nitrogen fertilization vs soil texture and weather. Proceedings of the NEV2013 Workshop on Nitrogen, Environment, and Vegetables, April 15-17, 2013, Turnin, Italy. NEV2013 Book of Abstracts: 45-46. Interpretive Summary:
Technical Abstract: Weather and soil properties are known to affect soil nitrogen (N) availability and plant N uptake. Studies examining N response as affected by soil and weather sometimes give conflicting results. Meta-analysis is a statistical method for estimating treatment effects in a series of experiments to explain the sources of heterogeneity. In this research, the technique was used to examine the influence of soil and weather parameters on N responses of corn (Zea mays L.) across 51 studies involving the same N rate treatments which were carried out in a diversity of North American locations between 2006 and 2009. Results showed that corn response to added N was significantly greater in fine-textured soils than in medium-textured soils. Abundant and well-distributed rainfall and, to a lesser extent, accumulated corn heat units enhanced N response. Corn yields increased by a factor of 1.6 (over the unfertilized control)in medium-textured soils and 2.7 in fine- textured soils at high N rates. Subgroup analyses were performed on the fine- textured soil class based on weather parameters. Rainfall patterns had an important effect on N response in this soil texture class, with yields being increased 4.5-fold by in-season N fertilization under conditions of “abundant and well-distributed rainfall.” These findings could be useful for developing N fertilization algorithms that would allow for N application at optimal rates taking into account rainfall pattern and soil texture, which would lead to improved crop profitability and reduced environmental impacts. The study shows how N savings could be substantial in vegetable crops if the interaction between soil texture and rainfall management is taken into account in the N rate decision-making process.