Odum School of Ecology, University of Georgia, Athens, Georgia, USA.
Soil and Water Science, University of Florida Gainesville, Florida, USA.
Nat Commun. 2015 Apr 30;6:6995. doi: 10.1038/ncomms7995.
The loss of organic matter from agricultural lands constrains our ability to sustainably feed a growing population and mitigate the impacts of climate change. Addressing these challenges requires land use activities that accumulate soil carbon (C) while contributing to food production. In a region of extensive soil degradation in the southeastern United States, we evaluated soil C accumulation for 3 years across a 7-year chronosequence of three farms converted to management-intensive grazing. Here we show that these farms accumulated C at 8.0 Mg ha(-1) yr(-1), increasing cation exchange and water holding capacity by 95% and 34%, respectively. Thus, within a decade of management-intensive grazing practices soil C levels returned to those of native forest soils, and likely decreased fertilizer and irrigation demands. Emerging land uses, such as management-intensive grazing, may offer a rare win-win strategy combining profitable food production with rapid improvement of soil quality and short-term climate mitigation through soil C-accumulation.
农业土地有机质的流失限制了我们可持续养活不断增长的人口和减轻气候变化影响的能力。应对这些挑战需要进行土地利用活动,在促进粮食生产的同时积累土壤碳(C)。在美国东南部土壤退化广泛的地区,我们在三个农场的 7 年时间序列中评估了管理集约化放牧 3 年后的土壤 C 积累情况。研究结果表明,这些农场每年可积累 8.0 Mg ha(-1) C,分别将阳离子交换量和持水量提高了 95%和 34%。因此,在管理集约化放牧实践的十年内,土壤 C 水平恢复到了原生森林土壤的水平,可能减少了化肥和灌溉的需求。新兴的土地利用方式,如管理集约化放牧,可能提供了一种罕见的双赢策略,通过土壤 C 积累,将有利可图的粮食生产与土壤质量的快速改善和短期气候缓解结合起来。