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通过17年大田长期定位试验,研究了在自然降水、一年一作春玉米种植制度下,有机无机肥配合施用时,0~300 cm褐土剖面硝态氮分布与累积的特点及农田氮素平衡。结果表明,适量的氮磷肥及合理的有机无机肥配比可显著提高作物产量,土壤氮素基本平衡;过低量的氮磷肥配施,土壤氮素处于亏缺状态;过高量的氮磷肥配施、有机肥及有机无机肥料配比,土壤氮素盈余显著增加。不同用量的长期单施化肥处理,施氮量超过120 kg/hm2后,硝态氮在土壤中有明显累积,硝态氮峰值出现在100~180 cm土层之间,且随施入氮素量的增加硝态氮峰值升高,以硝态氮形式残留在土壤剖面中的氮量占总施氮量的10.93%~44.24%。过高量有机无机肥配合施用处理,深层土壤硝态氮累积量大幅增加,淋失风险大大增强;有机无机肥配比适宜(N 120 kg/hm2,P 37.5 kg/hm2,M 22 500 kg/hm2,深层土壤硝态氮累积量显著下降,淋失风险低;单施高量有机肥同样会导致土壤硝态氮的累积。适量的氮磷肥用量及合理的有机-无机肥配比是提高作物产量、减少NO-3-N在土壤剖面中累积和淋失的有效措施。
Through 17 years of long-term field experiment, the characteristics of distribution and accumulation of nitrate nitrogen in 0-300 cm soil profile and nitrogen balance in farmland under natural precipitation, spring corn planting system of one year and organic-inorganic fertilizer application were studied. . The results showed that proper nitrogen and phosphorus fertilizers and reasonable proportion of organic and inorganic fertilizers could significantly increase crop yield and nitrogen balance was basically balanced. When too low amount of nitrogen and phosphorus fertilizers were applied, soil nitrogen was in a deficit state. With facilities, organic manure and organic and inorganic fertilizers ratio, soil nitrogen surplus increased significantly. Under long-term single application of chemical fertilizers with different dosage, nitrate nitrogen accumulated obviously in the soil with the nitrogen application rate exceeding 120 kg / hm2, and the peak value of nitrate nitrogen appeared between 100-180 cm soil layer, The increase of nitrate nitrogen increased with the amount of nitrogen remaining in the soil profile in the form of nitrate nitrogen accounting for 10.93% ~ 44.24% of the total nitrogen application. The organic matter and inorganic fertilizer with too high amount of treatment, the accumulation of nitrate in deep soil increased significantly, the risk of leaching greatly enhanced; organic and inorganic fertilizer suitable proportion (N 120 kg / hm2, P 37.5 kg / hm2, M 22 500 kg / hm2, the accumulation of nitrate nitrogen in deep soil decreased significantly, and the risk of leaching loss was low.Utilizing high amount of organic fertilizer could also lead to the accumulation of soil nitrate nitrogen.Appropriate amounts of nitrogen and phosphorus and proper proportion of organic-inorganic fertilizer were higher Yield, reduce NO-3-N in the soil profile of the accumulation and leaching of effective measures.