绿肥紫云英对稻田土壤系统氮素平衡的影响综述

Effect of Green Manure Chinese Milk Vetch on Nitrogen Balance in Paddy Soil System: A Review

为了系统了解稻田种植豆科填闲作物紫云英后氮素流通的变化情况,笔者综合阐述了紫云英对稻田土壤系统中氮素的输入、输出的影响,整体评价水稻-紫云英种植体系中氮素的平衡,结论主要包括:(1)紫云英能高效固氮并替代部分化肥、提高氮肥利用率;(2)通过提高水稻产量和氮含量,紫云英可以增加水稻收割携走氮量;(3)紫云英能够有效降低土壤氮素的径流损失;(4)紫云英可能具有降低土壤氮素淋溶损失的潜力,但是支撑数据较少;(5)紫云英能够显著减少稻田NH3挥发,但是对N2O的影响尚存争议。综上所述,紫云英在保障水稻产量的基础上,能够降低氮素损失所带来的环境风险,有效改善稻田土壤系统氮素平衡情况。

To systematically clarify the change of nitrogen circulation in paddy field after introducing Chinese milk vetch(Astragalus sinicus L.) as leguminous catch crop, this paper synthetically reviewed the effects of Chinese milk vetch on nitrogen(N) input and output in paddy soil and evaluated the N balance in rice-Chinese milk vetch cropping system. The conclusions mainly included:(1) Chinese milk vetch could effectively fix N and replace partial fertilizer, increase the N use efficiency;(2) by increasing rice yield and N content, Chinese milk vetch could raise N output through rice harvest;(3) Chinese milk vetch could effectively reduce N runoff loss;(4) Chinese milk vetch may have the potential to reduce nitrogen leaching loss, but the supporting data was limited;(5) Chinese milk vetch could significantly reduce NH3 volatilization in paddy fields, but the effect on N2O emission remained controversial at present. In summary, on the basis of maintaining rice yield, Chinese milk vetch could effectively reduce the environmental risk caused by N loss and ameliorate the N balance in paddy soil system.