摘要
摘要:农田复合系统是集约化农作的有效途径之一，在增加生物多样性和提高产量方面具有重要作用。干旱区农业生产中，温室气体减排和作物耗水减量是发展高效可持续农业的重要参考指标，研发基于作物复合生产的模式是该区节水、减排和可持续农业发展面临的重大课题。本研究以河西绿洲灌区长期规模化种植的小麦/玉米复合生产系统为对象，于2010-2012年度在甘肃农业大学校地联合绿洲农业科研教学基地（武威站），通过集成免耕立茬（NTS）、免耕秸秆覆盖（NTM）、少耕秸秆翻压（RTS）形成不同小麦/玉米间作复合系统，并以传统间作（CTI）为对照，重点研究了不同系统的土壤碳排放量和水分利用特征，比较分析了其生产效率和可持续性。结果表明，小麦和玉米复合系统的生物热能产较单作小麦提高113%，较单作玉米提高21%，该系统基于生物热能产的土地当量比均大于1。农田复合生产系统能有效降低土壤CO₂排放，特别是集成免耕秸秆覆盖的间作系统，土壤CO₂排放量比单作玉米降低12%，比传统间作降低13%，排放效率比单作玉米提高39%，比传统间作提高31%。此外，农田复合生产系统还显著降低了作物耗水，与传统间作相比，集成免耕秸秆覆盖的间作系统的棵间蒸发量、耗水总量和单位耗水碳排放量分别降低11%、5%和9%，但单位耗水生物热能产提高19%。农田复合生产系统较传统间作具有更高的土地当量比（1.78）、碳排当量比（1.48）和耗水当量比（1.22），三者分别提高14%、28%和20%，因而其可持续评价指数提高了13%。小麦/玉米间作集成免耕秸秆覆盖的农田复合生产系统可作为河西绿洲灌区高效可持续农作的可行模式。
关键词:小麦/玉米间作/
保护性耕作/
土壤CO₂排放/
水分利用/
生物热能产
Abstract:The integrated production system is effective for crop intensification and also plays an important role in improving biodiversity and grain yield. The reduction of greenhouse gas emissions and crop water consumption are important parameters in developing high-efficient and sustainable agriculture in arid areas. Researches on soil carbon emission, water use and characteristic of the integrated production system will benefit the productivity and sustainability of agricultural practices in this region. The experiment was carried out in 2011 and 2012 at the Oasis Agricultural Scientific Researching and Teaching Station of Gansu Agriculture University and Local Government, China. Wheat-maize intercropping system was used as the object of this study due to its long-term application in Hexi Oasis region. Through integration, different conservation practices, including no-till with stubble standing, no-till with stubble mulching, and reduced tillage with stubble incorporation were applied in wheat-maize intercropping system forming three integrated production systems (named NTS, NTM and RTS, respectively), with conventional intercropping (CTI), conventional monocropped maize (CTM) and wheat (CTW) as the control systems. The study mainly focused on soil carbon emission and water use characteristics of different cropping systems, and further compared the differences in system effectiveness and sustainability. Results showed that the energy yield of integrated wheat-maize intercropping system increased by 113% over monocropping wheat, and by 21% over monocropping maize, and the land equivalent ratios of integrated intercropping systems based on energy yield were greater than 1. The integrated system also significantly reduced soil CO₂ emission, especially for the NTM, of which, the soil CO₂ emission was reduced by 12% than CTM, and by 13% than CTI. Also, its' CO₂ emission efficiency increased by 39% over CTM, and by 31% over CTI. In addition, the integrated system significantly reduced the crop water consumption. Compared to CTI, NTM reduced evaporation, water consumption and carbon emission per unit of water by 11%, 5% and 9%, respectively. Nevertheless, the energy yield per unit of water improved by 19%. Compared to CTI, land (1.78), carbon (1.48) and water (1.22) equivalent ratios improved by 14%, 28% and 20% under NTM respectively. Therefore, the sustainability index was enhanced by 13% over the CTI. Consequently, the integrated wheat-maize production system can be used as a high-efficient and sustainable cropping model in the Hexi Oasis Irrigation Area.
Key words:Wheat-maize intercropping/
Conservation tillage/
Soil CO₂ emission/
Water utilization/
Energy yield



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