Effects of irrigation regulation of rural domestic reclaimed water on soil nutrients in paddy field
CHEN Suchun1,HU Jingbo2,XIAO Menghua3*,HU Xiujun4
1. Yongkang Water Resources and Water Supply Management Center, Yongkang, Zhejing 321300, China; 2. Hangzhou Xiaoshan Water Conservancy and Hydropower Survey and Design Co., Ltd., Hangzhou, Zhejiang 311200, China; 3. Zhejiang Institute of Hydraulics and Estuary(Zhejiang Institute of Marine Planing and Design), Hangzhou, Zhejiang 310020, China; 4. Zhejiang Institute of Water Conservan-cy and Ocean Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, Zhejiang 310018, China
Abstract：In order to study the effects of different irrigation water sources and water level regulation on soil nitrogen and organic matter nutrients, three irrigation water sources(rural domestic sewage primary treatment water R1, secondary treatment water R2, river clear water R3)and three irrigation water level regulations(the upper limit of sewage(rain)storage at low water level W1 is 50-70 mm, that at medium water level W2 is 50-100 mm, and that at high water level W3 is 50-150 mm)were selected to meet the requirements of farmland irrigation water quality. The results showed that NH4+-N was the main nitrogen in 0-40 cm soil layer, NO3-N content was low, NH4+-N was relatively stable, and there existed a changing trend of ″as one falls, another rises″, NO3-N was easier to migrate and accumulate with water. Irrigation with primary treatment water of rural domestic sewage can significantly improve the content of soil organic matter. Different water level regulations had significant effect on NO3-N content in 60-80 cm soil layer(P<0.05), and different water source irrigations had significant effect on soil organic matter content in 0-20 cm soil layer(P<0.05). Reclaimed water irrigation can significantly improve the yield of rice, and the average yield of rice under R1 water source irrigation was 1.5% and 14.3% higher than that under R2 and R3 water source irrigations, respectively.
