This study investigated the offset effect between green manure (GM) application and plastic film mulching (PFM) on soil organic carbon (SOC) stock change during maize cultivation. Within PFM and no-mulching treatments, three different fertilization sub-treatments were applied: (a) chemical fertilizer, (b) barley and (c) hairy vetch. The SOC balance were evaluated by analyzing the net ecosystem carbon budget (NECB). The results showed that the NECB value was negative during maize cultivation regardless of mulching or fertilization condition, indicated SOC loss. The PFM increased maize yield (P < 0.001) by improved soil moisture and temperature. Crop growth was enhanced under PFM relative to no mulching by 23–26%, 16–25% and 1–8% in the sub-treatments, respectively. However, PFM significantly increased carbon losses by 26–29%, 103–107% and 60–62% over no mulching in each fertilization, respectively (P < 0.001). the temperature sensitivity of CO₂–C loss was 52–70% higher in PFM than that in no mulching. Accordingly, the NECB was 1.3, 5.6 and 3.0 times lower with PFM relative to the no-mulching value in the three fertilization, respectively. Under no mulching, GM application reduced SOC loss by 33–59% compared with NPK, while under PFM, it accelerated SOC loss by 8–48%. Barley showed the smallest NECB decrease (− 1.0 Mg C ha⁻¹) under no mulching and the largest NECB decrease (− 5.7 Mg C ha⁻¹) under PFM. The findings indicate that GM application is not enough to sustain SOC stock under PFM and suggest that the additional recycling of crop residue, such as maize stover, is necessary to increase the soil C stock.

中文翻译：

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绿肥的施用加速了地膜覆盖下土壤有机碳的流失

这项研究调查了绿肥（GM）施用和塑料膜覆盖（PFM）对玉米种植期间土壤有机碳（SOC）储量变化的抵消效应。在PFM和免耕处理中，应用了三种不同的施肥子处理：（a）化肥，（b）大麦和（c）毛etch子。通过分析净生态系统碳预算（NECB）评估了SOC平衡。结果表明，无论覆盖条件或施肥条件如何，玉米栽培过程中NECB值均为负，表明SOC损失。PFM提高了玉米产量（P <0.001）通过改善土壤湿度和温度。与不覆盖相比，在PFM下，子处理的作物生长分别提高了23–26％，16–25％和1–8％。但是，在每次施肥不覆盖的情况下，PFM分别显着增加了碳损失26-29％，103-107％和60-62％（P  <0.001）。与不覆盖相比，PFM中CO ₂ -C损失的温度敏感性高52-70％。因此，相对于三个施肥中的非覆盖值，NECB的PFM分别低1.3倍，5.6倍和3.0倍。在不覆盖的情况下，与NPK相比，施用GM可使SOC损失降低33–59％，而在PFM下，施用GM可使SOC损失加快8–48％。大麦显示出最小的NECB下降（-1.0 Mg C ha ^-1）在不覆盖的情况下，在PFM下最大NECB下降（-5.7 Mg C ha ^-1）。研究结果表明，转基因作物的施用不足以维持PFM下的SOC储量，并建议增加玉米秸秆等农作物残渣的循环利用，以增加土壤C储量。