模拟降雨下植物篱-草沟系统茎秆直径对紫色土区泥沙粒径与氮磷迁移的影响OA

[Objective]This study aims to investigate the effects of the synergistic mechanism of the hedgerow-grass ditch system on the sediment particle sorting patterns and the migration and transformation processes of nitrogen and phosphorus.[Methods]Five combinations of hedgerows with stem diameters of 0(control,CK),0.1,0.2,0.4,0.8 cm,and with or without grass ditches(0,0.5 cm)were set up.A hedgerow-grass ditch system was constructed in the laboratory,and a simulated rainfall experiment was conducted under a rainfall intensity of 90 mm/h.The volume percentages of eroded sediment aggregates of 50-1 000 µm,2-50 µm,and less than 2 µm,as well as the transport characteristics of total nitrogen(TN)and total phosphorus(TP),were analyzed.[Results]1)In the hedgerow-grass ditch system,the eroded sediment aggregates were mainly composed of silt particles(2-50 µm).2)Under the conditions with and without grass ditches,the content of sand particles in the transported sediment on the slope with a stem diameter of 0 cm was significantly the highest(p<0.05).Under the condition with grass ditches,the TP contents of clay,silt,and sand particles in the transported sediment on the slope with a stem diameter of 0.8 cm were the lowest(p<0.05).3)Under the condition with grass ditches,the TN contents of three different particle sizes in the transported sediment on the slope with a stem diameter of 0 cm were the lowest.Among them,the treatment effects with stem diameters of 0.1 cm and 0.2 cm were significant(p<0.05).4)Under the condition with grass ditches,stem diameter was significantly negatively correlated with the TP content of the sand particles(p<0.05).Under the condition without grass ditches,stem diameter was significantly negatively correlated with the clay content,the TP content of silt particles,and TP content of sand particles(p<0.05).[Conclusion]The research findings provide a theoretical basis for the prevention and control of soil erosion and non-point source pollution in purple soil areas.