不同基因型小麦的氮吸收特征与农田归还率研究

为以控制农业面源污染为目标的高氮吸收小麦品种的选择与利用提供理论依据,研究了不同基因型小麦品种植株氮素吸收量及其在各部位的分布与归还特征。结果表明,不同基因型小麦品种植株氮吸收量存在不同程度的差异;32个小麦品种中7个品种属于高氮积累类型,平均氮吸收量为228.4kg·hm-2;小麦籽粒产量与植株氮吸收量呈显著正相关;小麦穗部氮吸收量最适于植株总吸氮量的估测,其估算方程为y=0.865x-1.843。秸秆不还田条件下,高吸氮量类型小麦品种收获后植株残体返回到农田的氮量为19.3kg·hm-2,占植株氮吸收量的9.4%;而在秸秆还田条件下,高吸氮量类型小麦品种植株残体返回到农田的氮量为46.1kkg·hm-2,占植株氮吸收量的20.9%。试验说明,高氮吸收小麦可以同时兼顾高产和农业生态环境保护;确定下茬作物的农田施氮量,除了考虑土壤地力和下茬作物养分需求因素外,还应该考虑还田作物含氮量。

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 7 of 32 varieties belonged to high nitrogen accumulation type,with the average nitrogen absorption amount of 228.4 kg·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 19.3 kg·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 46.1 kg·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 also agricultural 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.