生物可降解地膜覆盖对关中地区小麦-玉米农田温室气体排放的影响

为探究生物可降解地膜覆盖对冬小麦-夏玉米轮作农田生态系统温室气体排放的影响，布设了普通地膜覆盖（PM）、生物可降解地膜覆盖（BPM）和无覆盖（CK）这3个处理，采用静态暗箱-气相色谱仪法监测了2018～2019年土壤CO₂、 CH₄和N₂O的排放通量，并用水分利用效率（WUE）、温室气体排放强度（GHGI）和净生态系统经济预算（NEEB）指标评估覆膜对作物产量、农田环境和经济效益的影响.结果表明，与CK相比，PM和BPM增加了玉米季土壤CO₂的排放，PM处理下CO₂排放总量高于BPM处理（P>0.05）.PM和BPM处理均能够显著减少土壤对CH₄的吸收，CH₄的年吸收量较CK处理分别减少了42.0%和24.2%（P<0.05）.与CK相比，PM和BPM增加了小麦季N₂O排放总量（P>0.05）,而显著降低了夏玉米季N₂O排放（P<0.05）.覆膜能够提高作物产量和水分...

Effects of Biodegradable Plastic Film Mulching on Greenhouse Gas Emissions Under Wheat-Maize Rotation System in the Guanzhong Plain

In order to explore the effects of biodegradable plastic film mulching on the greenhouse gas emissions of a winter wheat-summer maize rotation system, the three treatments deployed in this experiment during a winter wheat-summer maize planting period from 2018 to 2019 included ordinary plastic film mulching (PM) and biodegradable plastic film mulching (BPM), with no film mulching as the control (CK). The emissions of soil greenhouse gases (CO₂, CH₄, and N₂O) were monitored using a static opaque chamber and chromatography methods. Moreover, the water use efficiency (WUE), greenhouse gas emission intensity (GHGI), and net ecosystem economic budget (NEEB) indicators were used to assess the impact of mulching on crop yield, farmland greenhouse effects, and economic benefits. The results of this study showed that compared with that of CK, the PM and BPM treatments increased soil CO₂ emissions during the summer maize growing season, and the cumulative CO₂ emission of the PM treatment was higher than that of BPM (P>0.05). Both the PM and BPM treatments significantly reduced the CH₄ absorption flux of the soil, and the annual absorption of CH₄ decreased by 42.0% and 24.2%, respectively, compared with that of CK (P<0.05). Furthermore, the PM and BPM treatments increased the cumulative N₂O emission flux in the wheat growing season (P>0.05) but significantly decreased the emissions of N₂O from soil in the maize season compared with that of CK (P<0.05). Film mulching increased crop yield and water use efficiency compared with those of CK, the wheat yield under the PM and BPM treatments increased by 51.7% and 32.3% (P<0.05), respectively, and the corresponding water use efficiencies were respectively increased by 33.1% and 36.3% (P<0.05). Similarly, in the summer maize season, the yield of PM and BPM increased significantly by 43.3% and 19.5% (P<0.05), and the water use efficiency increased by 49.8% and 18.4% (P<0.05), respectively. Combined with annual production and greenhouse gas emissions, PM and BPM reduced the GHGI by 20.5% and 14.8% (P>0.05) compared with that of CK, respectively, and PM significantly increased NEEB by 84.2% (P<0.05) compared with that of CK during the wheat-maize growing season, whereas BPM increased by 8.9% (P>0.05). To summarize, considering the yield, water use efficiency, environmental effects, and economic benefit, biodegradable plastic film mulching has the feasibility to replace ordinary plastic film mulching.