Abstract: A 4-year (2006-2009) field experiment was conducted to study the effects of different corn-wheat year-round tillage modes on the post-anthesis dry matter accumulation and transfer, grain-filling, and grain yield of winter wheat in a rain-fed farming area of southern Henan Province. Six modes including traditional tillage (T₁), non-straw mulching and pre-sowing shallow plough for corn + straw mulching and non-tillage for wheat (T₂), straw mulching and pre-sowing shallow plough for corn + non-straw-mulching and non-tillage for wheat (T₃), non-straw mulching and pre-sowing deep plough for corn + non-straw mulching and non-tillage for wheat (T₄), straw mulching and pre-sowing deep plough for corn + straw mulching and non-tillage for wheat (T₅), and non-straw mulching and pre-sowing shallow plough for corn + burying smashed straw in soil and rotor tillage (T₆) were examined. Among the test modes, T₁ and T₅ showed the best effects, under which, the leaf staying-green period of winter wheat was the longest, and the dry matter accumulation in vegetative organs was significantly higher (P<0.05) than that under other modes. Also, the transfer amount of the pre-anthesis assimilates in vegetative organs under T₁ and T₅ was higher, and the transfer amount and rate of post-anthesis assimilates in the vegetative organs were 11.9% and 11.7%, and 11.6% and 11.4% higher than those under T₃ and T₆, respectively (P<0.01). Under T₁ and T₅, the contribution of the post-anthesis assimilates to the grain yield of winter wheat was 8.4% and 7.9%, and 8.8% and 8.3% higher than that under T₃ and T₆ (P<0.05), and the grain yield was 7545.0 and 7480.5 kg·hm^-2, being 14.8% and 13.8% higher than that under T₆, respectively (P<0.01). Overall, mode T₅ had the best effect in promoting the dry matter accumulation in winter wheat vegetative organs and the transfer of post-anthesis assimilates to the grain, and also, played important roles in soil water conservation and fertility improvement, being considered as the high-efficient and high-yielding tillage mode for wheat production in the rain-fed farming area of southern Henan Province.

Key words: Intercropping, Root system, Wheat-soybean intercropping, Corn cabbage intercropping