绿肥轮作还田对稻田土壤溶液氮素变化及水稻产量的影响

Influence of Green Manure Crop on Nitrogen Concentration in Soil Solution of Paddy Field and Rice Yield

通过研究利用绿肥等改变轮作制度及N素管理后稻田土壤溶液中溶解性N素的动态变化及水稻产量的变化,评价了利用绿肥参与水稻轮作系统,减少无机N肥的施用量,促进水稻生长的同时降低环境负荷的可行性。研究表明,在总N量相当的情况下,冬绿肥还田或冬季休闲稻季土壤溶液中NH4+-N浓度均比稻麦轮作单施化肥的处理低。溶液NO3--N浓度随还田有机物料的C/N增加显著降低。利用豆科紫云英轮作还田,可降低44％的无机N肥用量,溶解性N浓度显著降低,是减小稻季N肥流失环境风险的有效途径。

Effects of green manure crops on concentration of inorganic nitrogen in soil solution of paddy fields and rice yield were studied to explore feasibility of reducing chemical fertilizer application through incorporating green manure crops into soil. Results showed that when the total N application rates were kept the same, compared with application of chemical fertilizer, combined application of organic material （green manure crops） and chemical fertilizer can significantly reduce NH4^＋ -N and NO3^- -N concentration in soil solution. Incorporating Chinese Milk Vetch into soil can reduce the chemical N fertilizer application rate by 44%, and also diminish the environmental risk ofN runoff.