Farmland runoff pollution ecological intercepting ditch

The invention relates to a farmland runoff pollution ecological intercepting ditch. The cross section of the ditch is trapezoid; the two walls and the bottom of the ditch are hardened by a concrete plate on which a plurality of rectangular holes are formed, and plants which have high capacity of absorbing nitrogen and phosphorus are planted in the holes; a plurality of check gates are arranged in the ditch; and the bottom of the ditch is provided with a plurality of filter boxes arranged in an S shape, holes are distributed on the four walls of each filter box all over, an adsorbing material which has high capacity of adsorbing the nitrogen and the phosphorus is filled in each filter box, and the plants which have high capacity of absorbing the nitrogen and the phosphorus are planted in the filter boxes. By the farmland runoff pollution ecological intercepting ditch, the nitrogen and the phosphorus in farmland drainage can be effectively intercepted, and the intercepting rate is over 50 percent and over 60 percent respectively; suspended matters in the farmland drainage can be effectively intercepted, and the intercepting rate is over 95 percent; the conventional farmland drainage ditch can be fully utilized, and the problem that ecological engineering occupies more cultivated land is solved; and engineering cost and maintenance cost are low, and the ditch is easy to operate and maintain and convenient to popularize and apply in a large area.