Study on the Effect of Paddy Field Wetland on the Prevention and Control of Phosphorus Non-point Source Pollution in the Southwest Hilly Area
This study took the typical paddy fields in Dazu disctrict of Chongqing as the research object,aiming to explore the"source"and"sink"effects of non-point source pollution and the phosphorus interception effect under the winter paddy field-rice planting mode.In-situ observations of the phosphorus concentration in the surface water and leachate of paddy fields were conducted during the fertilization period(March to May),the growing period(June to September),and the winter paddy field period(October to February of the following year).The results showed that the phosphorus concentration in the surface water and leachate during the fertilization period increased significantly,with average total phosphorus concentrations of 0.20 and 0.12 mg/L,respectively,which easily caused non-point source pollution.The phosphorus concentration in the surface water during the growing period remained at a high level,with an average total phosphorus concentration of 0.18 mg/L,while the phosphorus concentration in the leachate,especially the dissolved total phosphorus,showed a decreasing trend,with concentrations of 0.07 and 0.02 mg/L for total phosphorus and dissolved total phosphorus,respectively.The loss of surface water was the"source"of pollution,increasing the water storage capacity of paddy fields and transforming surface water into leachate could effectively control the loss of dissolved total phosphorus.During the winter paddy field period,the phosphorus concentration in the surface water and leachate was relatively low,with average total phosphorus concentrations of 0.09 and 0.03 mg/L,respectively,and the paddy fields became the"sink"of pollution.Therefore,promoting winter paddy fields for retention can play a role in controlling non-point source pollution.
paddy fieldphosphorusnon-point source pollutionrainfall controlleaching waterfield surface water
NETL
NSTL
万方数据
