Cropland soil organic carbon (SOC) is undergoing substantial alterations due to both environmental and anthropogenic changes. Although numerous case studies have been conducted, there remains a lack of quantification of the consequences of such environmental and anthropogenic changes on the SOC sequestration across global agricultural systems. Here, we conducted a global meta-analysis of SOC changes under different fertilizer managements, namely unbalanced application of chemical fertilizers (UCF), balanced application of chemical fertilizers (CF), chemical fertilizers with straw application (CFS), and chemical fertilizers with manure application (CFM). We show that topsoil organic carbon (C) increased by 0.9 (0.7–1.0, 95% confidence interval (CI)) g kg−1 (10.0%, relative change, hereafter the same), 1.7 (1.2–2.3) g kg−1 (15.4%), 2.0 (1.9–2.2) g kg−1 (19.5%) and 3.5 (3.2–3.8) g kg−1 (36.2%) under UCF, CF, CFS and CFM, respectively. The C sequestration durations were estimated as 28–73 years under CFS and 26–117 years under CFM but with high variability across climatic regions. At least 2.0 Mg ha−1 yr−1 C input is needed to maintain the SOC in ~85% cases. We highlight a great C sequestration potential of applying CF, and adopting CFS and CFM is highly important for either improving or maintaining current SOC stocks across all agro–ecosystems.
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机译：由于环境和人为因素的改变，农田土壤有机碳（SOC）正在发生重大变化。尽管已进行了大量案例研究，但仍缺乏这种环境和人为变化对全球农业系统中SOC隔离的后果的量化描述。在这里，我们对不同肥料管理下的SOC变化进行了全球荟萃分析，即化学肥料的不平衡施用（UCF），化学肥料的平衡施用（CF），秸秆化学肥料（CFS）和粪肥化学肥料应用程序（CFM）。我们表明，表土有机碳（C）增加了0.9（0.7-1.0，95％置信区间（CI））g kg -1 （10.0％，相对变化，此后相同），1.7（ 1.2–2.3）ggkg -1 （15.4％），2.0（1.9–2.2）ggkgkg -1 （19.5％）和3.5（3.2–3.8）ggkg在UCF，CF，CFS和CFM下分别为 -1 （36.2％）。在CFS下C的固存持续时间估计为28-73年，在CFM下C的固存持续时间为26-117年，但在整个气候区域之间差异很大。在〜85％的情况下，至少需要2.0 Mg ha -1 yr -1 C输入才能保持SOC。我们强调了应用CF的巨大C固存潜力，采用CFS和CFM对于改善或维持所有农业生态系统中的当前SOC存量非常重要。
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