AHDB, Stoneleigh Park, Kenilworth, Warwickshire, CV8 2TL, UK.
School of Healthcare Science, Manchester Metropolitan University, Manchester, M1 5GD, UK.
Sci Rep. 2017 Sep 5;7(1):10493. doi: 10.1038/s41598-017-11083-6.
Sequestration of atmospheric CO as organic carbon by agricultural soils (SOC) is promoted as a climate change mitigation option. IPCC provides guidelines for determining carbon stocks and sequestration potential, incentivising policy changes towards management of farmland for carbon sequestration. However, the basis of the assumption that agricultural soils can sequester significant atmospheric CO has been questioned. We sought to determine the potential for conversion of arable cropland to grassland to sequester carbon in the short to medium term and potential limiting factors. There were no differences in SOC stocks in the top 30 cm between grassland up to 17 years old and arable cropland at 14 sites across the UK. However, SOC showed different distribution patterns, being concentrated in the top 10 cm under grassland. Soil microbial communities were significantly different between arable and grassland, with higher biomass and lesser dominance by bacteria in grassland soils. A land use conversion experiment showed these changes occurred within one year of land use change. Failure of grassland soils to accumulate SOC was attributed to reduced available soil nitrogen, resulting in low productivity. The implications of these results for carbon sequestration in soils as a climate change mitigation strategy are discussed.
农业土壤（SOC）将大气 CO 隔离为有机碳，被认为是一种缓解气候变化的选择。政府间气候变化专门委员会（IPCC）提供了确定碳储量和固碳潜力的指南，鼓励政策朝着农田管理以实现碳固存的方向转变。然而，农业土壤可以大量固存大气 CO 的假设基础已经受到质疑。我们试图确定在短至中期内将耕地转化为草地以固碳的潜力及其潜在的限制因素。在英国的 14 个地点，在长达 17 年的时间里，草地的表层 30 厘米 SOC 储量与耕地之间没有差异。然而，SOC 表现出不同的分布模式，在草地下集中在表层 10 厘米。土壤微生物群落在耕地和草地之间有显著差异，草地土壤中的生物量较高，细菌的优势度较低。土地利用转换实验表明，这些变化在土地利用变化后的一年内就发生了。草地土壤未能积累 SOC 归因于可利用土壤氮的减少，导致生产力低下。这些结果对作为气候变化缓解策略的土壤碳固存的影响进行了讨论。
