Water Quality Purifying Effect in Paddy Field Irrigation Area
Abstract：A large amount of nitrogen and phosphorus in discharged water form paddy field cause serious agricultural non-point source pollution. A ＂Four Defense Lines＂ system of water-saving irrigation, field grass ditches, pond wetlands and ecological trunk ditches to purify the water discharged form paddy field is proposed in this paper. Experiment on the effect of reducing the pollution of drainage water form paddy field with this system has been conducted in Zhanghe Irrigation System, Hubei Province, China. Accord- ing to the result of the experiment, each subsystem under the ＂Four Defense Lines＂ mode is effective in re- ducing contamination, and the comprehensive system also has satisfactory effect on improving the water environment in paddy irrigation. The effects of reducing of total nitrogen, total phosphorus, ammonia ni- trogen and nitrite nitrogen by comprehensive system are 92.3%, 82.8%, 94. 4% and 64.6% respectively.
Keywords：four defense linesagricultural non-point source pollutionnitrogen and phosphorus mitigationwater-saving irrigationecological ditchpond wetland
Publication Date：2011-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)