The invention provides an ecological
ditch constructing method for controlling
nitrogen and
phosphorus in farmland drainage and relates to an ecological
ditch constructing method for the farmland drainage. The purpose of the invention is to solve technical problems of poor water flushing resistance and
low nitrogen and
phosphorus intercepting and purifying capacity in the traditional ecological
ditch constructing method for controlling
nitrogen and
phosphorus in the farmland drainage through arranging an ecological interceptor; and the ecological ditch constructing method provided by the invention is carried out in the following steps: first, planting plants on ditch walls and at ditch bottoms; and then arranging PVC pipes with holes at junctions of the ditch walls and the ditch bottoms; and arranging matrix intercept dams capable of replacing matrices at the ditch bottoms. The ecological ditch constructing method provided by the invention has the advantages as follows: without affecting normal drainage, the
hydraulic retention time is prolonged, excessive water flushing is resisted, and soils in the ditches are uneasy to slip; compared with the traditional ditch, the comprehensive
nitrogen and phosphorus purifying capacity of the ecological ditch is enhanced by 6-15 %; the capacity of intercepting and purifying nitrogen and phosphorus is strong; moreover, filled matrix of the matrix dam is
solid wastes, so that a purpose of controlling waste by waste is achieved; and the ecological ditch constructing method provided by the invention can be applied to the field of environmental
pollution prevention and water and
soil conservation.