长期稻-稻-紫云英轮作28年对水稻产量及田间杂草多样性影响

为探讨湘南红壤稻田多熟制的增产潜力，不断提高经济效益和土壤肥力，促进农业可持续发展，为生产示范、领导决策提供科学依据，从1982年开始，在湖南祁阳官山坪中国农业科学院红壤站的红壤稻田布置了长期稻-稻-紫云英轮作制度长期定位试验。试验设四个处理，即：稻-稻-紫云英（豆科）、稻-稻-油菜（十字花科）、稻-稻-黑麦草（禾本科）、稻-稻-冬闲。28年研究结果表明：1.长期稻-稻-紫云英轮作能促进水稻增产；2.长期稻-稻-紫云英轮作能够明显的降低田间杂草密度，减少早稻期间田间杂草的种类，但对晚稻时期田间杂草种类的影响不明显。3. 稻-稻-紫云英轮作是一种值得推广的种植模式。

Effects of Long-term Rice-Rice-Milk Vetch Rotation for 28 Years to Rice Yield and Weed Species Diversity

In order to study the potential yield of multiple cropping system about red soil rice field in Southern Hunan, continuously improve the economic benefit and soil fertility, promote agricultural sustainable development, provide scientific basis for production demonstrate and leadship decision-making. In order to study the effect of rice-rice-milk vetch rotation system, a long-term test had been arranging since 1982 in Red Soil Station of CAAS, which located in Guanshanping Qiyang Hunan. Four treatment was arranged in the test, that is rice-rice-milk vetch rotation（leguminosae）, rice-rice-oilseed rape（cruciferae）, rice-rice-rye grass （gramineae） and rice-rice-winter fallow. The results are as follows： Compared with winter fallow treatments, rice yield was increased under rice-rice-milk vetch rotation treatment; The density of weed species diversity was reduced obviously, the species was reduced on early rice, but not affected obviously on late rice; rice-rice-milk vetch rotation system is a worthy of popularizing planting mode.