Abstract:

Nitrogen and phosphorus losses from agricultural production is the main source of nutrient surplus in farmland ecosystems, water bodies and wetland ecosystems, leading to agricultural non-point pollution. Ecological ditch improves the effect of pollutant interception in the farmland drainage by upgrading and reforming the traditional farmland drainage ditch system, through forming the soil-microorganisms-plants balancing system with improving its metabolism to synergistically degrade the organic matter, nitrogen, phosphorus and other pollutants in the farmland drainage, as well as by the auxiliary denitrification and dephosphorization devices, interception and transformation pools and substrate contamination capture systems and other functional equipment. This case observed the concentrations of total nitrogen, phosphorus, ammonia and permanganate index to calculate their removal efficiency. The results indicated that ecological ditch significantly reduced the concentrations of ammonia, total nitrogen and phosphorus and devices in the ditch presented effective removal effect. This case provided effective technology to reduce agricultural non-point pollution in Xiaoshan District, and promote the development of green agriculture.

Key words: farmland nitrogen and phosphorus ecological interception ditch, interception and conversion pond device, drop weir, ecological permeable dam, total nitrogen, total phosphorus, ammonia nitrogen, permanganate index