The effects of greenhouse crops-rice cropping pattern on rice yield and non-point source pollution of nitrogen.

Field experiments with rice were conducted to study the differences in rice yield and nitrogen content of paddy field surface water between the rice-wheat cropping under conventional fertilization and the greenhouse crop-rice cropping without fertilization and the effect of N fertilization stages on the rice yield in greenhouse crop-rice cropping pattern.The results showed that at the early stage of rice growth,the total nitrogen content of paddy field surface water in the rice-wheat cropping under conventional fertilization was 5.02 times greater than that in the greenhouse crop-rice cropping without fertilization,and the rice yield in the former cropping pattern was 10.64% higher than that in the latter cropping pattern.When one-time nitrogen dressing(75 kghm2)was conducted at the leaf age remainder=4 or 5,the rice yield in the greenhouse crop-rice cropping without basal dressing could increase by at least 23% over that without fertilizer application.So the nitrogen application management had positive effects on increasing the rice yield in the greenhouse crop-rice cropping and decreasing non-point source pollution of nitrogen.