EXPERIMENTAL STUDY ON INTEGRATED METHODS OF WATER POLLUTION CONTROL IN RICE-BASED CROPPING SYSTEM, SOUTH OF CHINA

摘要

The overuse of irrigation water and chemical fertilizer and their ineffi cient use in rice productionof China have resulted in serious non-point source pollution. This has caused serious damagesto farmland water environment and ecology. In order to keep the non-point source pollutionproblem under control, the new concept, “Four Lines of Defence” comprising on-farm watersaving irrigation (WSI) in paddy fi elds, fi eld drainage ditches, construction of wetlands andecological trunk channels, have been developed and presented in this paper. In order to linkup the new theory with practice, fi eld experiments for each component were conducted inZhanghe Irrigation Scheme (ZIS), a typical rice-based irrigation systems, south of China, andthe effect on pollution mitigation and the overall treatment system are studied.