Buffering forest belts betweens farmlands and ditches can effectively stop and purify such elements as N and P in soil runoffs, thus controlling non-point source pollution of agricultural lands.

• 农田与沟渠间的缓冲林带具有截留和净化土壤径流中的N、P等物质的作用，从而在一定程度上控制农业非点源污染。