关键词: 轮茬作物, 养分还田特征, 水稻产量, 稻田水环境, 经济效益

Abstract:

A field experiment was conducted to study the nutrients （nitrogen, phosphorus and potassium） return characteristics of winter rotation crops and their effects on grain yield and main parameters of surface water environment during the successive rice growing season. The results showed that the yield and nutrients content of winter rotation crops were different significantly, which led to significant difference in the amount of nutrients returned to the paddy field under different winter crop-paddy rice rotation patterns. Under “Chinese milk vetch-paddy rice” rotation pattern, the amount of nitrogen （N） and phosphorus （P） were the highest. In the short term, the effects of winter crop rotation on the plant height, yield and fertilizer utilization of the subsequent rice were not significant. However, from the view of environmental effect, no matter what winter crop-paddy rice rotation patterns, during the rice growing season, the negative environmental impact of surface paddy water should be fully considered during the period from base fertilizer to tiller fertilizer. The monitoring results showed that the average contents of total phosphorus （TP） and dissolved phosphorus （DP） in the surface water of paddy rice field were almost higher than the critical level of water eutrophication （dissolved DP 0.05 mg/L; TP 0.1 mg/L）. Furthermore, from the perspective of annual economic benefits, higher income could be achieved under the green feeding winter wheat-rice rotation pattern and broad bean-rice rotation pattern, which might be further promoted and applied in the agricultural production of Taihu Basin, China.

Key words: winter rotation crops, nutrients return characteristics, grain yield, paddy water environment, economic benefits