地膜覆盖下粮油间作农田生产力与碳足迹评估

Assessment of Productivity and Carbon Footprint of Grain-Oil Intercropping Farmland under Plastic Film Mulching

摘要:

粮油间作与地膜覆盖作为适应特定自然条件的有效农业实践措施，在北方旱作农业生产中占有重要地位。此类农业措施应用势必影响农田土壤碳循环过程的改变，然而粮油间作与地膜覆盖下农田生产力与碳足迹的变化过程及伴生的生态环境效应尚不清楚。本研究设置了玉米覆膜单作（FMM）、玉米不覆膜单作（NMM）、大豆单作（SS）、玉米-大豆间作+玉米覆膜（FMS）、玉米-大豆间作+玉米不覆膜（NMS）5个处理，基于生命周期评价法对玉米-大豆间作与地膜覆盖下农田土壤温室气体排放特征、土壤有机碳含量、玉米产量等进行了评价，同时结合土地生产力和碳可持续性指数等指标综合评估了玉米-大豆间作与地膜覆盖对农田生产力与碳足迹的影响。两年试验结果表明，FMS处理相对产量较单作处理增加57%~60%，土地当量比两年均值为1.08，有效提高了农田土地生产力。同时，FMS处理土壤有机碳损耗相比其他处理减少7.8%~46.57%，且单位面积碳足迹（CFA）、单位玉米当量产量碳足迹（CFMEEY）和单位总收入碳足迹（CFE）最小，有效保存土壤有机碳的同时减小温室气体排放，降低了环境负担和碳排放。与单作种植系统相比，FMS处理虽然减少了部分作物产量和经济效益，但在生产过程中的土壤温室气体排放和有机碳损耗相对较低，与NMS处理相比也有更高的碳可持续性指数，实现了对土壤碳排放的有效管理。FMS作为一种环境友好型种植模式，可实现低碳高产，为农业生产者选择适宜种植系统提供了指导。

Abstract:

Intercropping of grains and oils, along with plastic film coverage, serves as an effective agricultural practice adapted to specific natural conditions. This practice holds significant importance in dryland agricultural production in the northern regions. The application of these measures is bound to influence the changes in the carbon cycling processes of farmland soil. However, the variations in productivity and carbon footprint under intercropping and plastic film coverage, along with the associated ecological effects, remain unclear. Totally five treatments, including maize mulching (FMM), maize without mulching (NMM), soybean monoculture (SS), maize-soybean intercropping + maize mulching (FMS), maize-soybean intercropping + maize without mulching (NMS) were set up. Based on the life cycle assessment (LCA) method, the characteristics of greenhouse gas emissions, content of soil organic carbon, corn yield, and other factors from farmland soil under maize-soybean intercropping and plastic film coverage were evaluated. It also comprehensively assessed the impact of these practices on farmland productivity and carbon footprint through indicators, such as land productivity and carbon sustainability index. The results indicated that the relative yield of FMS treatment was increased by 57% to 60% compared with that of monoculture treatment, with a land equivalent ratio of 1.08 over the past two years, effectively enhancing farmland productivity. Simultaneously, the soil organic carbon loss in the FMS treatment was reduced by 7.8% to 46.57% compared with that of other treatments. It exhibited the lowest carbon footprint per unit area (CFA), carbon footprint per unit maize equivalent yield (CFMEEY), and carbon footprint per unit total income (CFE), effectively preserving soil organic carbon while reducing greenhouse gas emissions, thereby alleviating environmental burdens and carbon emissions. Although FMS treatment reduced some crop yield and economic benefits compared with monoculture systems, it demonstrated relatively lower soil greenhouse gas emissions and organic carbon loss during the production process. It also had a higher carbon sustainability index compared with NMS treatment, achieving effective management of soil carbon emissions. FMS as an environmentally friendly planting model, it can realize low carbon and high yield, thus providing guidance for agricultural producers in selecting suitable planting systems.