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United States Department of Agriculture

Agricultural Research Service

Research Project: Conservation Systems Research for Improving Evnironmental Quality and Producer Profitability

Location: National Soil Dynamics Laboratory

Title: Conservation practices to enhance soil carbon sequestration across the Southeastern coastal plain

Authors
item BALKCOM, KIPLING
item Arriaga, Francisco
item Van Santen, Edzard -

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 10, 2013
Publication Date: September 16, 2013
Citation: Balkcom, K.S., Arriaga, F.J., Van Santen, E. 2013. Conservation systems to enhance soil carbon sequestration in the Southeastern U.S. Coastal Plain. Soil Science Society of America Journal. 77:1774-1783.

Interpretive Summary: A conservation system that promotes minimal surface disturbance combined with high residue cover crops can sequester carbon (C), but the ability to predict C sequestration amounts across specific conservation systems is not known at the field scale. Scientists with USDA-ARS located at the National Soil Dynamics Laboratory in Auburn, AL used a factorial arrangement of conservation tillage systems (no-till, fall paratill, spring paratill, and spring strip-till) and winter cover crops [no cover, rye (Secale cereal L.), and wheat (Triticum aestivum L.)] to evaluate biomass production of different cover crops and associated changes in soil organic C (SOC) with cover crop use, (ii) evaluate the potential of non-inversion tillage systems to sequester SOC after years of conventional tillage, and (iii) compare measured changes in SOC to predicted values obtained with the soil conditioning index (SCI). Cover crops added on average 2,500 kg C ha-1, while corn residue added 1,340 kg C ha-1 back to the soil each year. The conservation systems used in this study can sequester considerable amounts of C that will improve soil quality, and likely offset CO2 emissions in the Coastal Plain of the southeastern US.

Technical Abstract: A conservation system that promotes minimal surface disturbance combined with high residue cover crops can sequester carbon (C), but the ability to predict C sequestration amounts across specific conservation systems is not known at the field scale. A factorial arrangement of conservation tillage systems (no-till, fall paratill, spring paratill, and spring strip-till) and winter cover crops [no cover, rye (Secale cereal L.), and wheat (Triticum aestivum L.)] were established in a corn/cotton (Zea mays L./Gossypium hirsutum L.) rotation from 2004-2009 to evaluate biomass production of different cover crops and associated changes in soil organic C (SOC) with cover crop use, (ii) evaluate the potential of non-inversion tillage systems to sequester SOC after years of conventional tillage, and (iii) compare measured changes in SOC to predicted values obtained with the soil conditioning index (SCI). Cover crops averaged 2,500 kg C ha-1, while corn residue added 1,340 kg C ha-1 back to the soil each year. Soil organic C values measured after six years of tillage and cover crop combinations used in this study were weakly correlated with predicted SCI values (R2=0.37). Values calculated using a previously reported calibration equation overestimated SOC contents between 18 and 33%. This highlights the importance of rigorously testing models across a range of conditions and landscape scales. The conservation systems used in this study can sequester considerable amounts of C that will improve soil quality, and likely offset CO2 emissions in the Coastal Plain of the southeastern US.

Last Modified: 9/10/2014
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