化肥减量对紫色土坡耕地磷素流失的影响

采用人工径流小区对紫色土坡耕地降雨产流、磷素流失浓度进行定点观测,研究不施肥(CK)、常规施肥(T1)、优化施肥(T2)、化肥减量配施秸秆(T3)4种不同处理对紫色土坡耕地磷素在地表径流、壤中流中流失的影响.结果表明,壤中流是紫色土坡耕地的主要产流方式,占比高达70％以上,其中磷素主要通过泥沙、地表径流2个途径流失.化...

Effects of chemical fertilizer reduction on phosphorus loss in slope purple soil farmland

In this study, the artificial runoff plot was used to observe the rainfall runoff and phosphorus loss concentration in purple soil slope farmland. There were four treatments: no fertilizer application (CK), conventional fertilizer application (T1), optimized fertilizer application (T2), and reduced fertilizer combined with straw (T3) were set to study the phosphorus loss of interflow and surface flow in purple soil slope farmland. The results showed that the interflow was the main mode of flow of purple soil slope farmland, accounting for more than 70%, but phosphorus was mainly lost through sediment and surface runoff. The loss flux of total phosphorus in the treatment of reduced fertilizer combined with straw treatment was 0.412kg/(hm²·a), which was 29.37%~62.62% lower than other fertilization treatments. The orthophosphate loss flux showed the rule of optimized fertilization > conventional fertilization > reduced fertilizer combined with straw > non-fertilization, and the surface runoff loss flux was occupied 55.35%~84.65%. In the treatment of reduced fertilizer combined with straw application, the loss flux of particulate phosphorus in surface runoff was the lowest, which was significantly decreased by 70. 92% and 60. 28% compared with conventional fertilization and optimized fertilization, respectively. The treatment of reduced fertilizer combined with straw not only has an effective reduction effect on the loss of phosphorus in surface runoff, but also has a good reduction effect on the loss of phosphorus in interflow. Reduced fertilizer combined with straw is feasible to reduce the loss of phosphorus in purple soil slope farmland and reduce the risk of eutrophication in the Three Gorges Reservoir Area.