Water-saving and pollution-reducing effects of different irri-gation modes in paddy fields: A case study in Pinghu, Zhejiang province

Objective To study the water-saving and pollution reduction effects of rice under different irrigation modes, and to explore the water-saving irrigation mode suitable for the plain river network area. Methods Three modes of conventional irrigation, thin dew irrigation and suitable rain irrigation were set up in Pinghu irrigation experimental station in Zhejiang Province. The irrigation amount, TN, TP, , NO-N and COD in drainage and leakage water samples were measured. Result Compared with conventional irrigation and thin dew irrigation, the irrigation amount of suitable rain irrigation was reduced by 67.4% and 43.4%, respectively, and the water-saving effect was the best. Compared with conventional irrigation and thin dew irrigation, rain-appropriate irrigation has the least drainage. TN emissions, emissions, COD emissions and TP and emissions are reduced by 86.9% and 90.7%, 96.7% and 98.3%, 61.5% and 62.5%, respectively. Conclusion Under the condition of this study, the water-saving and pollution reduction effect of rain irrigation is better