Abstract：The aim of this study is to investigate the ecological effect of pre-flowering light deficit on the rhizosphere soil microbes of rice and provide the guidelines for the benign ecological cycle of soil and for the cultivation practice of super rice in light-poor areas. A super hybrid rice combination, "II Youhang 2", was used in the experiment under the field condition. Two shading intensities of 55% and 85% were set from jointing stage to initial heading stage in the experiment. The natural light condition was taken as the control. The results show that the amount of bacteria, actinomycetes, ammonifier, nitric acid bacteria, and aerobic azlotobacter has significantly declined with light deficient treatments at booting, initial heading, grain-filling, and harvest; in the meantime, the amount of fungi and denitrifier as well as desulphate has enhanced, and it results in the descent of the content of soil microbial metabolic biomass carbon and nitrogen. The factors inhibit the activities of soil urease and acid phosphatase. Moreover, the amount of bacteria, actinomycetes, ammonifier, nitric acid bacteria and aerobic azlotobacter is going down with the increasing intensity of light stress, and mutative trend of soil microbial metabolic biomass carbon and nitrogen, soil urease, and acid phosphatase is the same. However, the behavior of fungi and denitrifier as well as desulphate reducer are quite opposite to bacteria and actinomycetes. It is implied that pre-flower light deficit drops drown soil microbial metabolic biomass, alters soil microbial community, and undermines rhizosphere micro-ecological environment of the growth of rice.
2011, Vol. 29 
