【摘要】 本文以不施肥试验地设置供氮梯度试验（CK）,研究了不同供氮量(N1 40 kg·hm^-2、N2 80 kg·hm^-2、N3 1200kg·hm^-2、N4 160 kg·hm^-2、N5 200 kg·hm^-2、N6 240 kg·hm^-2)对水稻地上部生物量累积、氮素吸收、土壤无机氮残留和土壤氮素平衡的影响,可为集约化农田最大化发挥化肥生态效应和优化氮素管理提供理论依据和技术参考。结果表明:施氮对水稻生物量积累和氮素吸收利用有明显的影响,与不施氮对照相比,施氮处理显著增加了水稻生物量、氮浓度、吸氮量增幅分别为31.69%¹09.83%、15.08%～103.17%和54.18%³95.24%,其中N4水平增加量最大,之后有所降低;氮素吸收率、氮素利用率和氮素偏生产力氮浓度随施氮量增加呈先增加后降低趋势。整体上,土壤剖面无机氮含量自上而下呈现由高到低的变化,不同施氮处理间的差异主要体现在10 cm;0⁵0 cm剖面无机氮含量随施氮量增加显著增加,其中施氮量在240 kg·hm^-2间增加缓慢,施氮量高于160 kg·hm^-2后快速增加。从氮素主要的输入输出项来看,不同处理均有不同程度的盈余,大部分盈余氮素均在土壤0⁵0 cm剖面出现不同程度的累积。水稻土壤无机氮吸收量随着氮浓度的增加呈先增加后降低趋势,在氮浓度达到160 kg·hm^-2时达到最大,水稻土壤无机氮残留量呈相反的变化趋势。水稻有效穗、单株穗、结实率、产量和收获指数均随着氮浓度的增加呈先增加后降低趋势,在氮浓度达到160 kg·hm^-2时达到最大,之后有所降低。以上结果说明氮素对水稻生物量累积和氮素吸收利用起到一定的促进作用,但在施氮量高于160 kg·hm^-2后促进作用有所降低。综合考虑绿肥的农学和环境效应,水稻种植体系中土壤供氮量应控制在160 kg·hm^-2左右。更多还原

【Abstract】 With no fertilizer testbed Settings for nitrogen gradient test（CK）, was studied for different nitrogen(N1 40 kg·hm^-2, N2 80 kg·hm^-2, N3 1200 kg·hm^-2, N4 160 kg·hm^-2, N5 200 kg·hm^-2, N6 240 kg·hm^-2) accumulation of above ground biomass, n uptake of rice and soil inorganic nitrogen residue and soil nitrogen balance, for maximum intensive farmland exert the ecological effect of fertilizer and optimized nitrogen management to provide theoretical basis and technical reference. The results showed that nitrogen application had a significant impact on the biomass accumulation and nitrogen absorption and utilization of rice. Compared with the control group without nitrogen application, nitrogen application significantly increased the biomass, nitrogen concentration and nitrogen uptake of rice by31.69%, 15.08%, 103.17% and 54.18%, respectively.The nitrogen absorption rate, nitrogen utilization rate and nitrogen partial productivity concentration increased first and then decreased with the increase of nitrogen application.On the whole, inorganic nitrogen content in soil profile changed from high to low from top to bottom.The inorganic nitrogen content in the 0-50 cm profile increased significantly with the increase of nitrogen application, in which the nitrogen application increased slowly between 240 kg·hm^-2 and rapidly after the nitrogen application was higher than 160 kg·hm^-2. From the perspective of the main input and output terms of nitrogen,different treatments had different degrees of surplus, and most of the surplus nitrogen showed different degrees of accumulation in the0-50 cm section of soil.The inorganic nitrogen absorption in rice soil first increased and then decreased with the increase of nitrogen concentration, and reached the maximum when the nitrogen concentration reached 160 kg·hm^-2, and the inorganic nitrogen residue in rice soil showed an opposite change trend. Rice effective panicle, panicle per plant, seed setting rate, yield and harvest index all increased first and then decreased with the increase of nitrogen concentration, and reached the maximum when the nitrogen concentration reached160 kg·hm^-2, and then decreased.The above results indicated that nitrogen promoted the biomass accumulation and nitrogen absorption and utilization of rice to a certain extent, but the promotion decreased after the nitrogen application amount was higher than 160 kg·hm^-2.Considering the agronomic and environmental effects of green manure, soil nitrogen supply should be controlled around 160 kg·hm^-2 in the rice planting system.更多还原