The effects of rotary tillage with no stubble (RT), rotary tillage with straw incorporation (RTS), no-till without stubble (NT), no-till with 6 000 kg/ha (NTS 6000), and no-till with 3 000 kg/ha (NTS 3000), on weed communities structure and species diversity was studied in field experiments using a community ecology method. Compared with RT, the NT, NTS 3000, and NTS 6000 treatments increased perennial weed species, but there was no significant difference in the species richness. NT, NTS 3000 and NTS 6000 significantly reduced the summed dominance ratio (SDR) of Lithospermum arvense, but increased the SDR of Capsella bursa-pastoris. RTS significantly reduced the SDR of L. arvense, but increased the SDR of Descurainia sophia. The species diversity of weed communities varied significantly between different tillage systems. The Bray-Curtis index and hierarchical cluster analysis classified the weed communities of different tillage systems into two categories: Category I (NT, NTS 6000 and NTS 3000) where no-till was implemented, and category II (RTS and RT) where rotary tillage was implemented. The species richness of category I was a little larger than that of category II, but the species diversity and community evenness were much larger than those of category II. However, the community dominance of category I was significantly smaller than that of category II.
