稻虾共作模式下稻田杂草生长和群落多样性的调查

Investigation of Weed Growth and Community Diversity in the Rice-crayfish Symbiosis Farming

与常规种植相比,稻虾共作模式稻田中丁香蓼、水苋菜、千金子、陌上菜、稗草、通泉草、异型莎草、鲤肠、牛毛毡和铁苋菜频度均有所降低,而水莎草的频度则增加。当稻虾共作2~3年时,稻田杂草总密度、双子叶阔叶和单子叶禾本科杂草密度分别比常规模式降低了52.92%、73.53%和63.26%,当共作年限达到7~8年时,又较共作2~3年回升了67.39%、120.52%和290.66%,但仍比常规模式低。与常规种植模式相比,稻虾共作（2~8年）模式下稻田杂草丰富度指数、Shannon-Wiener指数、Pielou均匀度指数和Simpson优势度指数减少了32.71%~55.78%,而生态优势度则增加了48.37%~60.87%。随着稻虾共作时间的延长,稻田杂草发生和多样性表现出先减少后增加的趋势,并呈现出新的杂草群落结构。

Compared with rice conventionally grown, the frequency of Ludwigia prostrata, Ammannia baccifera, Semen Eu- phorbiae, Lindernia procumbens, Echinochloa caudata, Mazua miquelii, Cyperus difformis, Eclipta prostrata, Eleocharis and Acalypha australis reduced, and the frequency of JunceUus serotinus increased. The density, of total weed, Dicotyledon and Gramineae of 2-3 years rice-crayfish symbiosis farming reduced by 52.92%, 73.53% and 63.26% comparing to rice conventionally grown than 2-3 yers rice-crayfish symbiosis farming, and 7-8 years rice-crayfish symbiosis farming increased by 67.39%, 120.52% and 290.66%, respectively. When compared with rice conventionally grown, the weed richness, ShannonWiener index, Pielou evenness index and Simpson dominance index of the rice-crayfish symbiosis farming reduced by 32.71% -55.78%, but the ecological dominance of the rice-crayfish symbiosis farming increased by 48.37%-60.87%. As the period of the application of rice-crayfish symbiosis farming extended, the occurrence and diversity, of weeds in rice field showed a trend to decrease first and then increase, and presented a new structure of weed community.