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本试验采用连续两个轮作周期的稻麦轮作定位试验,研究了氮肥减施对作物氮素吸收、利用和土壤氮素平衡的影响。结果表明,在传统推荐施肥(小麦N 195 kg/hm2,水稻210 kg/hm2,均按底肥40%、分蘖肥30%、拔节肥30%分3次施用)的基础上,氮量减施20%,并配合综合调控技术措施,产量并没有降低,而且氮肥表观利用率、农学利用率、氮肥偏生产力和贡献率均得到提高。氮素在作物体内累积随着施量的提高而提高,土壤无机氮残留量和氮素表观损失也有相同的规律。生产相同数量的籽粒产量的需氮量小麦高于水稻,而氮素表观损失,则水稻高于小麦。
In this experiment, two successive cropping cycles of rice and wheat were used for locating experiments to study the effects of nitrogen application on crop nitrogen uptake and utilization and soil nitrogen balance. The results showed that on the basis of traditional recommended fertilization (wheat N 195 kg / hm2, rice 210 kg / hm2, all were applied 40% of base fertilizer, 30% of tillering fertilizer and 30% of jointing fertilizer) %, And combined with comprehensive regulation and control measures, the yield did not decrease, and the apparent nitrogen utilization, agricultural utilization, partial productivity and contribution rate of nitrogen fertilizers were all increased. Nitrogen accumulation in crop plants increased with increasing application rates. There was also the same pattern of soil inorganic nitrogen residues and apparent nitrogen loss. Nitrogen-producing wheat yielding the same amount of grain yield was higher than rice, whereas apparent nitrogen loss was observed, and rice was higher than wheat.