地膜水稻作为一种新的水稻种植方式, 在我国丘陵和山区水稻生产中具有明显的增产效果。地膜稻田中杂草作为重要的有害生物, 有关其群落组成及多样性的报道不多。为了明确地膜稻田杂草的种类、发生密度、优势种及群落多样性, 我们设计了地膜和常规种植两类不同种植模式稻田, 在田间杂草营养生长盛期, 抽样调查了两类稻田中杂草密度、发生程度及生物多样性指数等。结果表明: 地膜稻田和常规稻田杂草种类分别有8科12属12种和10科14属14种。其中常规稻田的马齿苋(Portulaca oleracea)、鸭舌草(Monochoria vaginalis)、拟金茅(Eulaliopsis binata) 和四叶萍(Marsilea quadrifolia) 等在地膜稻田不发生或仅偶有发生, 覆膜稻田中杂草总密度显著降低。异型莎草(Cyperus difformis)和酢浆草(Oxalis corniculata)在两种种植模式田均为优势种, 其相对密度分别为10.29-49.26%和11.91-45.59%, 且地膜稻田的密度均显著低于常规稻田; 而马唐(Digitaria sanguinalis)和水莎草(Juncellus serotinus)仅为地膜稻田的优势种, 其相对密度分别为18.01-30.46%和17.22-23.97%。除个别调查时间外, 两种种植模式稻田杂草群落的Shannon多样性指数和Margalef丰富度指数无显著差异; 而在整个调查期间, 地膜稻田的Pielou均匀度指数均显著高于常规稻田。由此可见, 地膜水稻种植模式不仅对稻田常见杂草和优势种杂草有一定的控制作用, 而且也使整个杂草群落处于一个稳定水平, 避免了一些杂草的暴发, 这对水稻生产过程中的草害控制具有重要的意义。

Mulch film is applied to and can greatly increase rice yield in mountainous and hilly areas of Central and Southwest China. Weeds are important pests in rice fields, but little knowledge exists about how mulch film impacts weed diversity in rice fields. Herein, we investigated the composition, density, and diversity of weed communities in film-mulched and conventional rice fields and compared species richness, total and relative densities, and diversity index of weeds between the two planting patterns. Twelve and 14 species of weeds were found in the film-mulched and conventional rice fields, respectively. Of them, Portulaca oleracea, Monochoria, vaginalis, Eulaliopsis binata and Marsilea quadrifolia, which occurred in conventional rice field, did not grow in the film-mulched rice field. Total weed density was suppressed in the film-mulched field compared to conventional rice field. Digitaria sanguinalis, Juncellus serotinus, Oxalis corniculata and Cyperus difformis were the dominant weed species and their relative densities were 18.01-30.46%, 17.22-23.97%, 11.91-45.59% and 10.29-49.26%, respectively. O. corniculata and C. difformis were found in both field types, but their densities were significantly lower in the film-mulched field than in the conventional rice field. D. sanguinalis and J. serotinus were dominant species found exclusively in the film-mulched rice field. In contrast with conventional rice fields, Pielou index was higher in the film-mulched rice field. Shannon and Margalef indices did not differ between planting patterns. Film-mulching was available for controlling weeds in paddy field and may be useful for maintaining weed communities at low levels and thereby avoiding severe weed outbreaks.