不同耕作与施肥方式对有机玉米田杂草群落和作物产量的影响

农田杂草是农业生态系统的重要组成部分。有机农田杂草控制是农业生产的一大难题,通过施肥方式改变杂草的竞争格局有望成为杂草控制的新途径。以暖温带有机玉米田为研究对象,设置了5种不同处理,即不施肥对照处理（CK）、施用牛粪处理（CM）、施用蚯蚓处理过的牛粪处理（EM）、免耕秸秆不覆盖处理（NT）和免耕秸秆覆盖处理（NS）,研究不同耕作和施肥方式对田间杂草密度、生物量、生物多样性及作物产量的影响。结果表明,在有机玉米农田内共发现杂草17种,CK杂草总密度最高,但杂草总生物量和生物多样性指数较低。EM杂草总生物量和牛筋草（Eleusine indica）生物量最高,分别比CK增加了192.6%和224.8%（P〈0.01）,物种丰富度和生物多样性指数较低,优势集中度指数较高。NS杂草总密度、总生物量和生物多样性与NT相比显著降低。此外,EM玉米（Zea mays）产量比CK高40.2%（P〈0.01）,比CM高19.6%（P〈0.01）。施用蚯蚓处理过的牛粪不仅提高了玉米产量,而且可以促进优势种杂草的生长,提高杂草群落的优势集中度。

Impact of Different Tillages and Fertilization Patterns on Weed Community and Corn Yield in an Organic Farmland

Weed, as an important component of agricultural ecosystem, is a difficult trouble in organic farming management. Applying different organic fertilizers to change the competitive pattern of weeds may be a new approach for weed control. We aimed to investigate the impact of different tillage and fertilization patterns on weed density, biomass, and biodiversity and crop yield in a temperate organic corn field. We used 5 treatments： no fertilization （CK）, cattle dung （CM）, earthworm manure （EM）, no-tillage （NT） and no-tillage with straw mulching （NS）. We found 17 species of weeds in the organic field. CK produced the highest total weed density, but the weed biomass and biodiversity index was lower than with CM and EM. EM produced the highest total weed biomass, and that of Eleusine indica increased by 192.6% and 224.8% （P〈0.01） as compared with CK. The species richness and biodiversity index was lower with EM than CK; however, EM produced the highest dominant concentration degree. Total weed density, total weed biomass and biodiversity were lower in NS than in NT. As well, the yield of maize was greater with EM than CK （increased 40.2%, P〈0.01） and CM. Thus, the application of cattle dung composted of earthworms could increase the yield of maize and the dominant con- centration of weed community in organic farmland.