摘要：
The response of light energy utilization and production benefit of crops to straw return to soils usually is important for establishing highly efficient cropping systems and optimizing cultivation practices. It is also the theoretical basis for exploring the cost-saving and benefits-increasing crop production in arid inland irrigation area. A field experiment was carried out in a typically irrigated oasis region in 2009–2012 in the Hexi Corridor of China to determine the effects on light energy utilization and production benefit of maize of different treatments of wheat straw return to soil and different tillage operations. The tillage and wheat straw re-tention operations included (i) no tillage with straw standing (NTSS), in which no tillage was combined with 25 to 30 cm high wheat straw standing in the field after wheat harvesting in the previous fall; (ii) no tillage with straw covering (NTS), in which no tillage was combined with 25 to 30 cm long wheat straw evenly spread on the soil surface at wheat harvest in the previous fall; (iii) tillage with straw incorporation (TIS), in which 25 to 30 cm long wheat straw was incorporated into the soil through conventional deep till-age (30 cm) at wheat harvest in the previous fall; and (iv) conventional deep tillage without wheat straw retention (as control), in which conventional deep (30 cm) plow was done with wheat straw removed from the field. The results showed that compared with the control, wheat straw retention treatments reduced leaf area duration (LAI-D) of maize before the large bell mouth stage, however, increased LAI-D of maize after silking, which effectively delayed senescence. No tillage with straw standing and straw covering (NTSS and NTS) had the best effects on senescence delay among all treatments, and the total LAI-D increased by 11.2% to 14.5% under NTSS, 16.3% to 20.8% under NTS and 6.0% to 7.5% under TIS, respectively; specifically, the increase in LAI-D under NTS treatment was the highest. Wheat straw retention had the effect of improving light use efficiency of maize field, and NTS treatment had the highest increasing effect, whose light use efficiency was 5.3% to 11.8% higher than that of the control. The previous wheat straw retention was favorable to increase grain yield of maize, and NTS treatment had the best increasing effect of grain yield, boosted grain yield by 13.7% to 17.5% compared with the control. NTSS and NTS treatments reduced the production cost, while improved the net return and the input-output ratio. NTS treatment had the large increasing range, increased the net return and the input-output ratio by 22.2% to 35.5% (3 953 to 5 200 ￥·hm-2) and 16.8% to 23.4%, respectively. Meanwhile, the water productivity and benefit per cubic meter water were improved by 13.7% to 17.5% and 25.6% to 33.1%, respectively. Based on the results there-fore, no tillage with 25 cm to 30 cm long wheat straw covering over soil surface (NTS) was the most suitable straw return strategy, which can be used as the key technology for cost-saving and benefits-increasing maize production in arid inland irrigation area.%研究前茬作物秸秆处理方式对后茬作物光能利用及水分生产效益的影响, 对于建立高效种植制度、优化栽培措施, 建立干旱内陆灌区作物生产的节本增效技术具有重要指导意义.2009—2012年, 在干旱内陆灌区, 通过田间定位试验, 研究了小麦不同秸秆还田方式(NTSS: 25~30 cm高茬收割立茬免耕; NTS: 25~30 cm高茬等量秸秆覆盖免耕; TIS: 25~30 cm高茬等量秸秆翻耕; CT: 传统无留茬翻耕)对后茬作物玉米光能利用及水分生产效益的影响, 以期为优化试区玉米种植模式提供依据.结果表明, 与 CT相比, 小麦秸秆还田降低了玉米大喇叭口期之前的叶日积(LAI-D), 但增大了吐丝期之后的LAI-D, 延缓了衰老; NTSS、NTS、TIS比CT处理玉米全生育期总LAI-D分别提高11.2%~14.5%、16.3%~20.8%、6.0%~7.5%, 以 NTS提高LAI-D幅度较大.秸秆还田有利于提高玉米籽粒产量, 以NTS增产效应更高, 较CT增幅为13.7%~17.5%.秸秆还田提高了玉米全生育期光能利用率, 以NTS提高作用最明显, 提高比例为5.3%~11.8%.NTSS、NTS可降低生产成本,提高纯收益与产投比, 以NTS最为突出, 比CT纯收益增加22.2%~35.5%(高3953~5200元·hm-2)、产投比增大16.8%~23.4%, 水分生产力与单方水效益分别提高13.7%~17.5%与25.6%~33.1%.因此, 小麦秸秆免耕覆盖(NTS)可作为河西绿洲灌区发展节本增效玉米生产关键技术.
