State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, PR China.
College of Earth Science, University of Chinese Academy of Sciences, Beijing, PR China.
Glob Chang Biol. 2021 Jun;27(12):2807-2821. doi: 10.1111/gcb.15607. Epub 2021 Apr 9.
Globally, about 50% of all arable soils are classified as acidic. As crop and plant growth are significantly hampered under acidic soil conditions, many farmers, but increasingly as well forest managers, apply lime to raise the soil pH. Besides its direct effect on soil pH, liming also affects soil C and nutrient cycles and associated greenhouse gas (GHG) fluxes. In this meta-analysis, we reviewed 1570 observations reported in 121 field-based studies worldwide, to assess liming effects on soil GHG fluxes and plant productivity. We found that liming significantly increases crop yield by 36.3%. Also, soil organic C (SOC) stocks were found to increase by 4.51% annually, though soil respiration is stimulated too (7.57%). Moreover, liming was found to reduce soil N O emission by 21.3%, yield-scaled N O emission by 21.5%, and CH emission and yield-scaled CH emission from rice paddies by 19.0% and 12.4%, respectively. Assuming that all acid agricultural soils are limed periodically, liming results in a total GHG balance benefit of 633-749 Tg CO -eq year due to reductions in soil N O emissions (0.60-0.67 Tg N O-N year ) and paddy soil CH emissions (1.75-2.21 Tg CH year ) and increases in SOC stocks (65.7-110 Tg C year ). However, this comes at the cost of an additional CO release (c. 624-656 Tg CO year ) deriving from lime mining, transport and application, and lime dissolution, so that the overall GHG balance is likely neutral. Nevertheless, liming of acid agricultural soils will increase yields by at least 6.64 × 10 Mg year , covering the food supply of 876 million people. Overall, our study shows for the first time that a general strategy of liming of acid agricultural soils is likely to result in an increasing sustainability of global agricultural production, indicating the potential benefit of liming acid soils for climate change mitigation and food security.
全球范围内，约有 50%的可耕地土壤呈酸性。由于作物和植物在酸性土壤条件下的生长受到严重阻碍，因此许多农民，越来越多的森林管理者开始施用石灰来提高土壤 pH 值。除了对土壤 pH 值的直接影响外，石灰施用还会影响土壤碳和养分循环以及相关的温室气体（GHG）通量。在这项荟萃分析中，我们回顾了全球范围内 121 项基于现场的研究中报告的 1570 个观测结果，以评估石灰施用对土壤 GHG 通量和植物生产力的影响。我们发现，石灰施用可使作物产量显著增加 36.3%。此外，土壤有机碳（SOC）储量每年增加 4.51%，但土壤呼吸也受到刺激（增加 7.57%）。此外，石灰施用还可使土壤氮氧化物排放量减少 21.3%，氮氧化物排放标准化产量减少 21.5%，稻田甲烷排放和甲烷排放标准化产量分别减少 19.0%和 12.4%。假设所有酸化农业土壤都定期进行石灰施用，那么由于减少了土壤氮氧化物排放（0.60-0.67 吨氮氧化物-N 年）和稻田土壤甲烷排放（1.75-2.21 吨甲烷 年）以及增加了 SOC 储量（65.7-110 吨碳 年），石灰施用可带来 633-749 万吨二氧化碳当量的温室气体综合效益。然而，这需要付出代价，即石灰开采、运输和应用以及石灰溶解会额外释放约 624-656 万吨二氧化碳，因此总体温室气体平衡可能为中性。尽管如此，酸化农业土壤的石灰施用仍将使产量至少增加 6.64×10^8 吨/年，足以满足 8.76 亿人的粮食供应。总体而言，我们的研究首次表明，普遍采用酸化农业土壤石灰施用策略可能会提高全球农业生产的可持续性，表明石灰施用酸化土壤对于缓解气候变化和保障粮食安全具有潜在的益处。
