Plastic film mulch is used widely in rainfed areas to increase crop yields, and the addition of biochar to soil has been proposed as an effective measure for reducing greenhouse gas emissions. Comprehensive analysis is required to assess the effects of plastic film mulching combined with adding biochar on the net ecosystem carbon budget (NECB), greenhouse gas emissions, and water use efficiency (WUE) in farmland ecosystems. Therefore, we tested the following six treatments in a three-year (2018–2020) field trial: no mulching or added biochar (NM); biochar applied at 4.5 t ha^–1 without mulching; biochar applied at 9.0 t ha^–1 without mulching; plastic film mulch without biochar application (PM); biochar applied at 4.5 t ha^–1 with plastic film mulching; and biochar applied at 9.0 t ha^–1 with plastic film mulching (PMH). The results showed that plastic film mulching improved the maize yield (20.22%), greenhouse gas emissions (CO₂: 22.57%; N₂O: 17.58%), NGWP (net global warming potential; 15.19%), and CF (carbon footprint; 13.97%), but the effect on NECB did not differ significantly from that under NM (P > 0.05). Compared with PM, PMH reduced the CO₂ (3.24%) and N₂O (26.44%) emissions, increased the absorption of CH₄ by 65.55%, and significantly increased NECB. Under PMH, the maize yield, WUE_g (water use efficiency of grain), and PUE_g (precipitation use efficiency of grain), increased by 6.40%, 10.14%, and 6.92%, respectively, whereas the NGWP, GHGI (greenhouse gas intensity), and yield-scaled CF decreased. Therefore, PMH simultaneously improved the productivity, production efficiency (WUE, PUE, and yield-scaled CF) and soil carbon budget in rainfed farmland, as well as reducing greenhouse gas emissions into the atmosphere, and thus it is a possible sustainable management method for farmland in rainfed areas.

塑料薄膜覆盖物广泛用于雨养地区以提高作物产量，并且已提出将生物炭添加到土壤中作为减少温室气体排放的有效措施。需要进行综合分析来评估地膜覆盖和添加生物炭对农田生态系统净生态系统碳收支 (NECB)、温室气体排放和水分利用效率 (WUE) 的影响。因此，我们在为期三年（2018-2020）的田间试验中测试了以下六种处理方法：不覆盖或添加生物炭（NM）；施用 4.5 t ha ^–1的生物炭，无需覆盖；以 9.0 t ha ^–1施用生物炭，无需覆盖；不使用生物炭 (PM) 的塑料薄膜覆盖物；生物炭施用量为 4.5 t ha ^–1用地膜覆盖；生物炭 9.0 t ha ^–1使用塑料薄膜覆盖 (PMH)。结果表明，地膜覆盖提高了玉米产量（20.22%）、温室气体排放（CO ₂：22.57%；N ₂ O：17.58%）、NGWP（净全球变暖潜能值；15.19%）和CF（碳足迹） ; 13.97%), 但对 NECB 的影响与 NM 下无显着差异( P  > 0.05)。与PM相比，PMH减少了CO ₂（3.24%）和N ₂ O（26.44%）的排放，增加了对CH ₄的吸收65.55%，显着增加了NECB。在 PMH 下，玉米产量、WUE _g（粮食水分利用效率）和 PUE _g（粮食的降水利用效率）分别提高了 6.40%、10.14% 和 6.92%，而 NGWP、GHGI（温室气体强度）和产量尺度的 CF 下降。因此，PMH 同时提高了雨养农田的生产力、生产效率（WUE、PUE 和产量尺度 CF）和土壤碳收支，同时减少了温室气体排放到大气中，因此它是一种可能的可持续管理方法雨养地区的农田。