Achieving Soil Organic Carbon Sequestration with Conservation Agricultural Systems in the Southeastern United States

• Published in: Soil Science Society of America journal Vol. 74; no. 2; pp. 347 - 357
• Main Author: Franzluebbers, Alan J
• Format: Journal Article
• Language: English
• Published: Madison Soil Science Society 01.03.2010; American Society of Agronomy
• Subjects: Agricultural conservation; Agricultural land; Agricultural management; Agricultural practices; Carbon; Carbon sequestration; chronosequences; conservation practices; conservation tillage; conventional tillage; crop management; Crop residues; Crop rotation; Ecosystem services; Emissions; environmental monitoring; Farm buildings; Farming systems; gas emissions; Greenhouse gases; Land degradation; land management; literature reviews; methodology; Organic carbon; Organic matter; Pasture; pastures; Soil conservation; soil depth; Soil erosion; Soil fertility; soil organic carbon; Soil organic matter; soil sampling; Soil surfaces; Soils; spatial variation; temporal variation; Tillage; Water quality; Southeastern United States; United States > US; USA, Southeast
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj2009.0079

Conservation management of degraded land has the potential to build soil fertility, restore soil functions, and mitigate greenhouse gas emissions as a consequence of surface soil organic matter accumulation. Literature from the southeastern United States was reviewed and synthesized to: (i) quantitatively evaluate the magnitude and rate of soil organic C (SOC) sequestration with conservation agricultural management; (ii) evaluate how conservation management affects surface SOC accumulation and its implications on ecosystem services; and (iii) recommend practical soil sampling strategies based on spatial and temporal issues to improve the detection of statistically significant SOC sequestration. Soil organic C sequestration was 0.45 ± 0.04 Mg C ha–1 yr–1 (mean ± standard error, n = 147, 20 ± 1 cm depth, 11 ± 1 yr) with conservation tillage compared with conventional tillage cropland. Establishment of perennial pastures sequestered 0.84 ± 0.11 Mg C ha–1 yr–1 (n = 35, 25 ± 2 cm depth, 17 ± 1 yr). Stratification of SOC with depth was common under conservation agricultural management and appears to be integrally linked to abatement of soil erosion, improvement in water quality, and SOC sequestration. Sampling of conservation management systems should ideally occur repeatedly with time in controlled and replicated experiments, but there is also an urgent need for chronosequence and paired-field surveys of SOC on working farms in the region to validate and expand the scope of inference of experimental results. Landowners in the southeastern United States have great potential to restore soil fertility and mitigate greenhouse gas emissions with the adoption of and improvement in conservation agricultural systems (e.g., continuous no-till, high-residue crop rotations, high organic matter inputs).