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采用田间试验结合15 N同位素示踪,研究有机无机肥配施对浙江省杭嘉湖平原稻田氮素利用率及环境效应的影响,结果表明:在施氮量150kg/hm2基础上,加施有机肥3 000kg/hm2,稻谷增产9.8%～17.7%,氮素利用率达到47.9%,比单施化肥提高4.8%。而在施氮量210kg/hm2的基础上增施有机肥,稻谷产量及氮素利用率均呈下降趋势。硝态氮是稻田土壤氮素损失的主要形式,施用有机肥能有效地降低氮素损失率。在施氮量150kg/hm2基础上配施有机肥,氮素通过田间径流的流失率由0.85%降至0.70%,氮素通过渗漏水损失率由1.29%降至0.96%;施氮量达到210kg/hm2后,施用有机肥对减少氮素流失的效果不明显。综合考虑试验点土壤特性、施肥目标产量以及对农田环境污染的潜在风险,建议以每1hm2施用纯氮150kg、配施3 000kg有机肥较为适宜。
The field experiment and 15 N isotope tracer were used to study the effects of organic and inorganic fertilizers application on the nitrogen utilization and environmental effects of paddy fields in Hangjiahu Plain of Zhejiang Province. The results showed that applying organic fertilizers 3 000kg / hm2, paddy yield 9.8% ~ 17.7%, nitrogen utilization rate reached 47.9%, which was 4.8% higher than that of chemical fertilizer alone. However, applying organic fertilizers on the basis of 210 kg / hm2 nitrogen application rate, rice yield and nitrogen utilization rate showed a decreasing trend. Nitrate is the main form of nitrogen loss in paddy soils. Application of organic fertilizer can effectively reduce the rate of nitrogen loss. The application of organic manure on the basis of 150 kg / hm2 of nitrogen application decreased the runoff loss rate of nitrogen from 0.85% to 0.70% and the loss rate of nitrogen leakage water from 1.29% to 0.96% 210kg / hm2, the application of organic fertilizer to reduce the effect of nitrogen loss is not obvious. Considering the soil characteristics of the experimental site, the target yield of fertilization and the potential risk to the farmland environmental pollution, it is recommended to apply 150kg of pure nitrogen per 1hm2 with 3 000kg of organic fertilizer.