Effect of Nitrogen Fertilizer on Characteristic of Nitrogen Metabolism and Yield after Anthesis of Wheat in the High Fertility Soil of North Henan

This study was to investigate the effects of nitrogen fertilizer on the characteristic of nitrogen metabolism after anthesis and yield of wheat grown under high fertility soil.The effects of five N application levels(0,150,200,250 and 300 kg·hm-2) on GS activity,free amino acid content,yield and protein content in the flag leaf and kernel,and NO3-N content in different soil layers from 0 to 100 cm were investigated with aikang-58 as tested material under field condition.The results indicated that the 200 kg·hm-2 N application can greatly improve the GS activity,free amino acid content in the flag leaf and kernel.There was no significant difference between the 250 kg·hm-2,300 kg·hm-2 and 200 kg·hm-2 N application levels.After harvest of wheat,the residue of NO3-N content in different soil layers from 0 to 100cm increased with the increase of N fertilization rate.The spike number and grain protein improved with the increase of N fertilization rate,but the 1000-kernel weight decreased with the increase of N fertilization rate.The highest yield(9 529.35 kg·hm-2) was achieved under the 200 kg·hm-2 N application,and the middle yield was achieved under the 250 kg·hm-2 N application,and the lowest yield was achieved under the 300 kg·hm-2 N application.The yield under 300 kg·hm-2 N application was significantly less than that under 200 kg·hm-2 and 250 kg·hm-2.So,the 200 kg·hm-2 was recommend as the optimal N application for the ultimate goal of achieving high-yield.