不同稻作方式对稻田杂草群落的影响

运用半试验与调查相结合的方法，以贵州省从江县传统农业区的糯稻和杂交稻为例，研究了在水稻单作（R）、稻-鱼（R-F）和稻-鱼-鸭（R-F-D）3种不同稻作方式下稻田杂草群落的特征.结果表明：糯稻在3种稻作方式下的抑制杂草能力均优于杂交稻；R-F-D显著降低了田间杂草的发生密度，对鸭舌草、节节菜等的抑制效果达到100%，总体抑制杂草效果显著优于其他稻作方式,杂草的物种丰富度及Shannon多样性指数显著降低，Pielou均匀度指数提高，表明群落物种组成发生了很大的改变，降低了原来优势杂草的发生, 是一种较好的可达到抑制杂草效果的稻作方式.

Effects of different rice farming systems on paddy field weed community

Taking the paddy fields planted with glutinous rice and hybrid rice inthe traditional agricultural region in Congjiang County of Guizhou Province as the case, and by using semi-experiment combined with random sampling investigation, this paper studied the characteristics of weed community in the paddy fields under rice monoculture (R), rice-fish culture (R-F), and rice-fish-duck culture (R-F-D). Under the three rice farming systems, glutinous rice had highercapability in inhibiting weeds, compared with hybrid rice. Farming system R-F-D decreased the weed density significantly, with the control effect on Monochoia vaginalis and Rotala indicabeing 100%. The overall weed-inhibiting effect of R-F-D was significantly higher than that of the other farming systems. Under R-F-D, the species richness and Shannon diversity index of weed community decreased markedly, while the Pielou evenness index increased, indicating that the species composition of weed community changed greatly, and the occurrence of native dominant weed species decreased. It was concluded that R-F-D was a feasible farming system for the control of paddy field weed community.