Study on Fertilization Effect under the Rotation System of Fertilizer-Rice-Rice in Jianghuan Area

[Objective]The study aimed to discuss the rational ratio of Chinese vetch and inorganic fertilizer and their application effect. [Method]With the early rice variety Zaoian 7038 and late rice variety WUyunjing 7 as the test materials,the effects of mixed application of Chinese vetch and chemical fertilizer on the rice yield and its yield components were studied.[Result]In the early rice test,when the application rate of chemical fertilizer was decreased by 30%,the yield of early rice was increased with the rising of the mixed application rate of Chinese vetch and the early rice had optimum yield-increasing effect in the treatment of mixed application of Chinese vetch at 22 500 kg/hm~2, being 8.2%higher than that in the treatment of applying 100%chemical fertilizer.In the late rice test,the yield of late rice was increased with the rising the of the application rate of Chinese vetch in the previous crop planting and that in the treatment of mixed application of Chinese vetch at 30 000 kg/hm~2 in the previous crop planting was highest,being slightly higher than that in full chemical fertilizer treatment. [Conclusion]The increased application of chemical fertilizer and mixed application of Chinese vetch could improve the parameters of yield components and the mixed application of Chinese vetch at high rate in the previous crop planting could get optimum the yield-increasing effect on the yield of late rice.