Nitrogen Use Efficiency and Related Parameters In Winter Wheat Varieties Common To The Great Plains USA.

Increasing nitrogen use efficiency (NUE) in winter wheat can help producers reduce input costs associated with nitrogen fertilizers and reduce environmental risk of N loss. Many studies have investigated management impacts on NUE, however very few have investigated effects of crop genetics. The objective of this study was to determine if there are differences in NUE among 30 wheat varieties commonly grown in the Great Plains. The experiment was a field study in Rossville, Kansas with treatments consisting of N rate and variety. The wheat varieties were grown with two N rates, 0 lb N ac^-1 and 90 lb N ac^-1. Nitrogen use efficiency was calculated as the grain yield per unit of available nitrogen (sum of soil N and fertilizer N). Although there appeared to be varietal differences in nitrogen use efficiency, there was a high amount of variability in the data and results were not statistically significant (p>0.23). Nitrogen content in the grain and biomass production efficiency were the only two parameters significantly affected by variety (p<0.05). This suggests that some varieties may be able to produce biomass with less N and remobilize it to the grain during reproductive growth. However, more research will be needed to develop firmer conclusions.