Effects of different corn/wheat year-round tillage modes on post-anthesis dry matter accumulation and transfer and grain yield of wheat in rain-fed farming area of Southern Henan Province

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(P0.05) 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(P0.01) .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(P0.05) ,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(P0.01) .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.