Effects of Nitrogen Reduction on Wheat Yield and Quality in Different Ecological Environments

Abstract

Abstract The effects of different nitrogen applications on wheat yield and quality under different ecological conditions were investigated to provide a reference for the synergistic objectives of green cultivation and high yield to improve the quality and efficiency of wheat in Yunnan Province, China. Three wheat cultivars and a total of four fertilizer gradients of 450kg/ha, 360kg/ha, 270kg/ha, and 0kg/ha urea application rate divided by two times, 50% of the base fertilizer and 50% of the jointing stage fertilizer, are as treatments. Our results indicated the yield was lowest when no fertilizer (0 kg/ha) was applied. However, the amount of nitrogen fertilizer required for the highest yield varies for different varieties and environments. Yunmai76 and Yunmai77 had the highest yield at urea application of 360 kg/ha, and Yun122-329 had the highest yield at urea application of 270 kg/ha. The yield difference between locations was highly significant, with the highest yield in Linxiang, followed by Ning'er County and the lowest yield in Yanshan County. Ning'er, with the south subtropical mountain monsoon climate, had the highest yield at urea application of 360Kg/ha, and Linxiang, with the subtropical mountain monsoon climate, had the highest yield at urea application of 450 kg/ha. With the low-latitude north subtropical highland monsoon climate, Yanshan County had the highest yield at urea application of 270 kg/ha. The quality indexes of the same variety varied greatly in different ecological environments, and there were large differences in the quality of different varieties at the same ecological site; the protein content, flour yield, hardness index, dough development time, dough stable time, wet gluten content, sedimentation value and water absorption of each variety were low when no nitrogen fertilizer was applied and was highest or second highest when 360 kg of urea was applied. The peak of each quality index required different amounts of nitrogen fertilizer in different ecological zones. In summary, to archive high yield, wheat varieties require no more than 360 kg urea per hectare but vary among different ecological environments.