Nitrogen Absorption Characteristics and Return Rate of Different Genotypes of Wheat Cultivars

In order to provide guidance for the selection and utilization of high-nitrogen-accumulation wheat varieties,the characteristics of nitrogen absorption,distribution and return of 32 wheat varieties were studied.The results showed that different genotypes of wheat varieties had significantly different nitrogen uptake.Clustering analysis showed that 7of 32 varieties belonged to high nitrogen accumulation type,with the average nitrogen absorption amount of 228.4kg·hm-2.There was significant positive correlation between plant nitrogen absorption and wheat grain yield.Panicle nitrogen absorption amount was the most suitable for the estimation of total plant nitrogen absorption amount,and the estimating equation was y=0.865x-1.843.Under the condition of no straw incorporation,nitrogen return by ploughing plant residue into field after harvest was 19.3kg·hm-2 for high nitrogen absorption type of wheat varieties,which account for 9.4% of plant nitrogen uptake.However,with straw incorporation,nitrogen return by ploughing plant residue into field after harvest was 46.1kg·hm-2 for high nitrogen absorption type of wheat varieties,which account for 20.9% of plant nitrogen uptake.The results suggested that in the current intensive agricultural production,planting crop varieties with high nitrogen absorption ability can give overall consideration of high yield and alsoagricultural ecological environment protection.The determination of the following fertilizer application amount should consider the crop variety returned into field besides soil fertility and nutrient demand of the following crop.