不同缓释肥施用比例对桃树-大豆间作农田地表径流氮、磷流失及土壤养分的影响

Effects of Different Proportions of Slow-release Fertilizer on Nitrogen and Phosphorus Loss from Surface Runoff and Soil Nutrients in Peach-Soybean Intercropping System

针对滇池流域坡耕地不合理施肥、农业面源污染风险大的现状,试验通过在滇池流域桃树-大豆间作模式下施用不同比例的缓释肥(处理Ⅰ(2/3缓释肥+1/3复合肥)、处理Ⅱ(全部施用缓释肥)、CK(全部施用复合肥)),对在自然降雨形成的地表径流进行了采样与分析,研究了不同比例缓释肥施用对农田地表径流中氮、磷流失量的影响;同时,通过定期对土壤样品的采集与分析研究了施用不同比例的缓释肥对土壤养分及物理性质的影响。结果表明:与CK相比,处理Ⅰ与处理Ⅱ的总氮流失量分别削减了16.77%和24.99%,铵氮流失量分别削减了24.65%和29.74%,硝氮流失量分别削减了16.06%和30.42%,总磷流失量分别削减了31.51%和34.60%。随着时间的推移,全部施用缓释肥可以使0—20cm和20—40cm 2个土层的养分含量显著高于对照。因此,在桃树-大豆间作模式中,施用缓释肥显著降低了氮、磷流失量,并提高了土壤中养分含量。

Based on the current situation of unreasonable fertilization and high risk of agricultural non-point source pollution in sloping farmland of Dianchi Lake basin,a field experiment was conducted,in which different proportions of slow-release fertilizer（treatment I（2/3slow-release fertilizer ＋ 1/3compound fertilizer）,treatment Ⅱ（slow-release fertilizer）and CK（compound fertilizer））were applied in peach-soybean intercropping model system.By collecting and analyzing the surface runoff and soil samples in all treatments,we studied the influence of different proportions of slow-release fertilizer on nitrogen and phosphorus loss in surface runoff from farmland,and on soil nutrients and chemical characteristics.The results showed that compared to the loss amount in CK treatment,loss of total nitrogen reduced by 16.77% and 24.99%,loss of ammonia nitrogen reduced by 24.65% and 29.74%,and loss of nitrate nitrogen reduced by 16.06% and 30.42%in treatmentⅠ andⅡ,respectively.Loss of total phosphorus in treatmentⅠ and Ⅱ reduced by 31.51% and34.60%.Soil nutrient contents in 0—20cm and 20—40cm layers in slow-release fertilizer treatment were significantly higher than those in CK treatment.The results indicated that application of slow-release fertilizer could significantly reduce the loss of nitrogen and phosphorus in peach-soybean intercropping system and improve soil nutrient status.