Opportunities to increase soil carbon sequestration in grazing lands in the southeastern United States

Background

Grazing lands provide numerous ecosystem services, including the capacity to store large amounts of soil carbon (C); however, our understanding of the factors affecting soil C responses to management is inadequate.

Methods

In this paper, we synthesized information about the impacts of grazing land management on soil C within the southeastern region of the United States.

Results

Most studies (68%) demonstrated that proper management increased soil C stocks with an average C accumulation rate of 1.4 Mg C ha⁻¹ year⁻¹. The remaining (32%) studies showed no effect of management on soil C. None of the studies reported negative impacts of management on soil C. The largest increase in soil C (8 Mg C ha⁻¹ year⁻¹) was associated with the conversion of cropland to pastureland while overseeding legumes into grass pastures resulted in the lowest C sequestration rates (0.2 Mg C ha⁻¹ year⁻¹).

Conclusions

Considering the rates of soil C accretion and the extensive area occupied by grazing lands, data in this synthesis confirm that the adoption of improved management practices can increase soil C sequestration in the southeastern United States. In addition, because most improved management practices can also have co-benefits, they may be favorable for forage and livestock production and other ecosystem services.