SOIL CARBON SEQUESTRATION IN SOIL CONSERVATION MANAGEMENT SYSTEMS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0219069
• Project Start Date: Oct 1, 2009
• Project End Date: Sep 30, 2014
• Program Code: [(N/A)]- (N/A)

Recipient Organization
OKLAHOMA STATE UNIVERSITY
(N/A)
STILLWATER,OK 74078

Performing Department
Plant & Soil Sciences

Non Technical Summary
The recent development of a carbon credit market has initiated a great interest in the sequestration of atmospheric CO2 into agricultural soils throughout the U.S. In 2001, Oklahoma legislature passed the Oklahoma Carbon Sequestration Enhancement Act which authorized the Oklahoma Conservation Commission to establish and administer a carbon sequestration certification program for the state. Direct assessment of soil carbon storage using scientifically sound methods, local knowledge of environmental and land management factors affecting soil carbon storage is needed. This will improve the accuracy of carbon sequestration rates used to estimate carbon credits gained in Oklahoma. Research plots established in native Oklahoma grassland soil show that 110 years of cultivation removed 46-70 % of the original organic carbon in the surface 15 cm of soil(Girma et al., 2007). Numerous studies have shown that eliminating tillage will allow for accumulation of soil organic carbon (Follet, 1993; Havlin et al., 1990; and Lal et al., 1999). Tillage aerates the soil and stimulates the decomposition of organic matter from microbial respiration (Curtain et al., 2000). Removing tillage from the systems reduces soil microbial respiration and allows organic carbon to accumulate. Other factors such as initial organic matter content, soil aeration, soil moisture and soil temperature influence soil respiration (Jingyum et al., 1998). The rate of organic carbon accumulation results from the balance between these factors that influence respiration and factors that control crop residue input into the soil system. Increasing crop residue input to the soil through optimizing crop yield and or intensification of crop rotations has been shown to be positively correlated with soil carbon concentrations (Sherrod et al, 2003). In Oklahoma where the factors controlling both soil respiration and crop residue input can vary due to the diverse soils, climatic conditions, and production systems, it is critical that carbon sequestration be evaluated carefully. Two soil conservation land management practices are considered viable alternatives for agricultural carbon credits. They are no-till crop production and the establishment of grasslands on previously cultivated crop land. The proposed research will focus on verifying estimates of carbon sequestration rates under these practices and determination of the production, climate and soil factors that significantly influence carbon sequestration in Oklahoma. Recently, the use of shallow sampling depths (0-15 cm) to estimate soil carbon sequestration has come into question. It has been suggested that utilization of soil samples collected from the surface tillage layer results in an over-estimation of carbon sequestration because it fails to account for the redistribution of organic carbon at deeper depths within the profile when tillage is utilized (Baker et al., 2007; Gal et al., 2007; Venterea et al., 2006). Therefore, the proposed research will evaluate soil carbon storage above and below the historic tillage depth to ensure accurate carbon sequestration estimates.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
101	0110	1070	60%
101	0799	1070	20%
101	1599	1070	20%

Knowledge Area
101 - Appraisal of Soil Resources;

Subject Of Investigation
0110 - Soil; 0799 - Rangelands and grasslands, general; 1599 - Grain crops, general/other;

Field Of Science
1070 - Ecology;

Keywords

soil carbon

no-till

grasslands

co2 sequestration

soil conservation

Goals / Objectives
The objective of the proposed research is to assess soil carbon sequestration under soil conservation management practices, specifically no-till crop management and grassland establishment.

Project Methods
Three approaches will be utilized to assess the rate of soil carbon sequestration under soil conservation management practices. The first two approaches will utilize farmer-cooperator fields and consist of sampling "paired fields." Samples will be collected from these fields to provide baseline data for long-term assessment of carbon storage. The third approach will involve the collection of soil samples from ongoing experiments in Oklahoma that include treatments that represent soil conservation management practices such as no-till crop production and grassland establishment in previously cultivated soils. Paired fields will be selected such that they contain similar soil types and slope class. One field of each pair will be in conventional tillage crop production management and the other will be in soil conservation management system. Fields that have been converted to grasslands or no-till crop management will be compared to cultivated fields. This approach will allow for a rapid estimate of carbon sequestrations rates for soils in Oklahoma crop production regions. The fields will be sampled to provide baseline data for long-term assessment of carbon sequestration in soils under conservation management. Many of these fields will be those utilized for the paired field comparisons. These will be sampled at 3 and 5 years after initial sample collection so that direct measurements of soil carbon sequestration can be achieved. This type of assessment of carbon sequestration will provide data that will represent the diversity of crop production environments found in Oklahoma. Soil samples will be collected along 200 meter transects in these fields. Along each transect three sample locations will be utilized. Three cores will be collected within a 2 m2 area. These sample locations will also be marked using GPS. The slope along the transect will also be measured. The third approach will utilize ongoing small plot cropping systems experiments located in Oklahoma. Experiments that provide for a direct comparison of soil organic carbon content in soils under cultivation and no-till management will be utilized. Sampling these experiments will provide assessment of soil carbon storage under various crop rotations utilized in the state under different climatic and soil conditions. Data will be collected to evaluate the impact of fertilizer management, harvest frequency, and grass species on soil carbon storage. Soil samples collected for this project will be taken to a minimum depth of 40 cm. Each core will be sectioned into 0-10, 10-20 and 20-40 cm increments. Soil bulk density will be determined for each depth. Soil samples will be analyzed for moisture content after oven-drying. Total C and N will be determined by high temperature combustion using a TrueSpec CN analyzer. Soil inorganic C will be determined using a pressure calcimeter method (Sherrod et al., 2002). Soil organic carbon will be determined by the difference between total carbon and inorganic carbon. Soil pH will be determined with an electrode on a 1:1 soil:water paste.

Progress 10/01/09 to 09/30/14

Outputs
Target Audience: crop producers, land owners, Ag professionals and government agencies Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The following undergraduate students work on this project: Blake McGowen, Dept. of Plant and Soil Sciences Blake Farrow, Dept. of Plant and Soil Sciences Wella Wasabi, Environmental Science The following graduate student work on this project: Sumit Sharma, Dept. of Plant and Soil Sciences Tracy wilson, Dept. of Plant and Soil Sciences How have the results been disseminated to communities of interest? The results have been publised in extension publications, Reports to the EPA, and through various presentations at scientific meetings and extension education meetings. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The results collected from this project have demonstrated that the carbon content of Oklahoma soils varies widely as a function of soil type and environmental conditions. This variation along with the large mass of carbon found in surface soils make it difficult to accurately assess the impacts of the multiple variables that influence carbon sequestration in a short period of time. Our efforts have quantified the variability on measured carbon stocks to allow us to determine the number of samples required to monitor carbon in fields under contract for carbon credits. This combined with our efforts to determine effects of probe type on carbon stock measurements as well as laboratory method develop allowed us to develop and evaluate a sampling protocol to be used by the Oklahoma carbon program to monitor carbon stocks in cropland under contract for carbon offset payments. This to our knowledge is the first protocol of its kind to be tested in the field. The evaluation performed was very useful in determining not only the accuracy and precision with which carbon can be practically monitored but also allowed us opportunity to evaluate the cost of such a monitoring effort. Unfortunately, the value of carbon offsets is currently very low due to a lack of interest in voluntary purchases. However, our efforts have prepared the Oklahoma Carbon Program for the future potential of marketing carbon offsets generated by soil carbon sequestration if demand develops as a result of mandatory caps on greenhouse gas emissions.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: 2. Warren, J.G., S. Sharma, A.E. Cumbie, T.M. Wilson, and T.E. Ochsner. 2013. Sources of variability in organic carbon stocks: can we overcome them? In ASA-CSSA and SSSA abstracts. Available online at: https://scisoc.confex.com/scisoc/2013am/webprogram/Paper82626.html
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: 5. J.G. Warren, T.M. Wilson. 2013. Delivery of extension education on climate change mitigation and adaption. In ASA-CSSA and SSSA abstracts. Available online at: https://scisoc.confex.com/scisoc/2013am/webprogram/Paper82624.html

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Government agency personnel Carbon credit aggregators Landowners Agricultural producers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? 1 graduate student was trained during this reporting period How have the results been disseminated to communities of interest? Conference presentations and through inclusion of findings as support material for the Oklahoma Carbon program What do you plan to do during the next reporting period to accomplish the goals? I plan to continue efforts to monitor carbon stocks in cropping systems in Oklahoma

Impacts
What was accomplished under these goals? The results collected from this project have demonstrated that the carbon content of Oklahoma soils varies widely as a function of soil type and environmental conditions. This variation along with the large mass of carbon found in surface soils make it difficult to accurately assess the impacts of the multiple variables that influence carbon sequestration in a short period of time. Our efforts have quantified the variability on measured carbon stocks to allow us to determine the number of samples required to monitor carbon in fields under contract for carbon credits. This combined with our efforts to determine effects of probe type on carbon stock measurements as well as laboratory method develop allowed us to develop and evaluate a sampling protocol to be used by the Oklahoma carbon program to monitor carbon stocks in cropland under contract for carbon offset payments. This to our knowledge is the first protocol of its kind to be tested in the field. The evaluation performed was very useful in determining not only the accuracy and precision with which carbon can be practically monitored but also allowed us opportunity to evaluate the cost of such a monitoring effort. Unfortunately, the value of carbon offsets is currently very low due to a lack of interest in voluntary purchases. However, our efforts have prepared the Oklahoma Carbon Program for the future potential of marketing carbon offsets generated by soil carbon sequestration if demand develops as a result of mandatory caps on greenhouse gas emissions. We will continue research efforts to provide an improved understanding of carbon cycling in Oklahoma soils such that sound recommendations can be made to optimize carbon sequestration estimates and ensure the quality of carbon credits generated in Oklahoma.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: 1. Warren, J.G., S. Sharma, A.E. Cumbie, T.M. Wilson, and T.E. Ochsner. 2013. Sources of variability in organic carbon stocks: can we overcome them? In ASA-CSSA and SSSA abstracts. Available online at: https://scisoc.confex.com/scisoc/2013am/webprogram/Paper82626.html
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: 2. J.G. Warren, T.M. Wilson. 2013. Delivery of extension education on climate change mitigation and adaption. In ASA-CSSA and SSSA abstracts. Available online at: https://scisoc.confex.com/scisoc/2013am/webprogram/Paper82624.html
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: 3. Sharma, S., J. Warren, A. Cumbie, and T. Wilson. 2013. Feasibility of soil carobn monitoring for carbon credits. In SWCS Abstracts. Available online at: http://www.swcs.org/documents/filelibrary/13ac/2013_Abstract_Book_A7E9CA4864695.pdf
• Type: Other Status: Accepted Year Published: 2013 Citation: 1. Warren, J.G., K. Meeks, T.M. Wilson. 2013. North Canadian River Watershed 319 Special Project Report. 17 Oct. 20pp.

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: The results of this project are primarily being disseminated through the Oklahoma Carbon Program. This is a voluntary program administered by the Oklahoma Conservation Commission in cooperation with the Oklahoma Association of Conservation Districts. The program provides increased quality to carbon credits produced in Oklahoma through verification that land management is sufficient to result in the accumulation of soil organic carbon. The data collected thus far has been used to educate participants of carbon credit trading. These participates include aggregators, landowner, Oklahoma Conservation District personnel and Oklahoma Conservation Commission personnel. The data produced has also been disseminated at regional and international conferences, including the International Soil and Water Conservation Society Conferences and the ASA-CSSA-SSSA International Annual Meeting. PARTICIPANTS: The following undergraduate students work on this project: Blake McGowen, Dept. of Plant and Soil Sciences Blake Farrow, Dept. of Plant and Soil Sciences Wella, Environmental Science The following graduate student work on this project: Sumit Sharma, Dept. of Plant and Soil Sciences These students assist with research activities associated with this project. Sumit's research project focuses on developing a soil sampling protocol to be used for monitoring soil carbon stocks in cropland under contract for carbon credit payments. The following faculty members in the Department of Plant and Soil Sciences are collaborators in this project: Chad Godsey, Assistant Professor Tyson Ochsner, Assistant Professor Gopal Kakani, Assistant Professor The following Oklahoma Conservation Commission personnel are collaborators in this project: Stacy Hansen, Oklahoma Carbon Program, Director. TARGET AUDIENCES: Government agency personnel Carbon credit aggregators Landowners Agricultural producers Efforts will be made to utilize the information gather from this project in improve their knowledge about the management required to sequester soil organic carbon and the rate at which different production systems sequester soil organic carbon. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The results collected from this project have demonstrated that the carbon content of Oklahoma soils varies widely as a function of soil type and environmental conditions. This variation along with the large mass of carbon found in surface soils make it difficult to accurately assess the impacts of the multiple variables that influence carbon sequestration in a short period of time. However, continued research efforts will provide an improved understanding of carbon cycling in Oklahoma soils such that sound recommendations can be made to optimize carbon sequestration estimates and ensure the quality of carbon credits generated in Oklahoma.

Publications

• Sharma, S., and J. Warren. 2012. Collecting soil samples to measure soil carbon stocks. PT-2012-6. Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK. Dec.
• Sharma, S., J. Warren, T. Wilson, A. Cumbie. 2012. Assessment of sampling methods for carbon credit monitoring. In SWCS Abstracts. Available online at: http://www.swcs.org/documents/filelibrary/12ac/2012_Abstract_Book_7B7 F4A470290D.pdf
• Sharma, S., A. Cumbie, T. Wilson, J. Warren. 2011 Assessment of sampling methods for carbon credit monitoring. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Pandey, A., V.G. Kakani, and J. Warren. 2011. Evaluation of root characteristics of different switchgrass cultivars. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Warren, J., T. Wilson, and C. Godsey. 2011. Rapid assessment of carbon sequestration in southern plains no-till management. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Wilson, T.M., and J. Warren. 2011. Carbon cycling in perennial biofuel management systems. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Wilson, T.M., and J. Warren. 2010. Changes in estimates of carbon stocks in a high shrink/swell soil. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Cumbie, A., J.G. Warren, B. Arnall. 2011. Organic matter in no-till production systems. PSS-2267. Oklahoma State University, Stillwater, OK. Dec.
• Warren, J., and C. Godsey. 2010. Summary of the soil carbon sequestration assessment program. CR-2265. Oklahoma Cooperative Extension Service, Oklahoma State University, Stillwater, OK. Oct.

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: The results of this project are primarily being disseminated through the Oklahoma Carbon Program. This is a voluntary program administered by the Oklahoma Conservation Commission in cooperation with the Oklahoma Association of Conservation Districts. The program provides increased quality to carbon credits produced in Oklahoma through verification that land management is sufficient to result in the accumulation of soil organic carbon. The data collected thus far has been used to educate participants of carbon credit trading. These participates include aggregators, landowner, Oklahoma Conservation District personnel and Oklahoma Conservation Commission personnel. The data produced has also been disseminated at state conferences such Oklahoma Association of Conservation Districts. The data was also presented at the ASA-CSSA-SSSA International Annual Meeting and the Soil and Water Conservation Society conference. PARTICIPANTS: Austin Hudson, Dept. of Plant and Soil Sciences Andrew Whitaker, Dept. of Plant and Soil Sciences Clayton Elder, Environmental Science Amanda Rauh, Natural Resources and Ecology Management Amanda Barns, Dept. of Plant and Soil Sciences The following graduate student work on this project: Tracy Wilson, Dept. of Plant and Soil Sciences Alex Cumbie, Dept. of Plant and Soil Sciences Sumit Sharma, Dept of Plant and Soil Sciences These students assist with research activities associated with this project. Tracy Wilson's research project focuses on the assessment of carbon sequestration in cellulosic bioenergy production systems. The following faculty members in the Department of Plant and Soil Sciences are collaborators in this project: Chad Godsey, Assistant Professor Tyson Ochsner, Assistant Professor Gopal Kakani, Assistant Professor The following Oklahoma Conservation Commission personnel are collaborators in this project: Stacy Hansen, Oklahoma Carbon Program, Director. TARGET AUDIENCES: Government agency personnel Carbon credit aggregators Landowners Agricultural producers Efforts will be made to utilize the information gather from this project in improve their knowledge about the management required to sequester soil organic carbon and the rate at which different production systems sequester soil organic carbon. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The results collected from this project have demonstrated that the carbon content of Oklahoma soils varies widely as a function of soil type and environmental conditions. This variation along with the large mass of carbon found in surface soils make it difficult to accurately assess the impacts of the multiple variables that influence carbon sequestration in a short period of time. However, continued research efforts will provide an improved understanding of carbon cycling in Oklahoma soils such that sound recommendations can be made to optimize carbon sequestration estimates and ensure the quality of carbon credits generated in Oklahoma.

Publications

• Warren, J.G., T.M. Wilson and C. Godsey. 2011. Rapid Assessment of Carbon Sequestration Potential of No-till in the Southern Plains. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Abreu, S., C.B. Godsey, J.T. Edwards, and J.G. Warren. 2011 Assessing Carbon and Nitrogen Stocks of No-till Systems in Oklahoma. Soil & Tillage Research 117:28-33.

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: The results of this project are primarily being disseminated through the Oklahoma Carbon Program. This is a voluntary program administered by the Oklahoma Conservation Commission in cooperation with the Oklahoma Association of Conservation Districts. The program provides increased quality to carbon credits produced in Oklahoma through verification that land management is sufficient to result in the accumulation of soil organic carbon. The data collected thus far has been used to educate participants of carbon credit trading. These participates include aggregators, landowner, Oklahoma Conservation District personnel and Oklahoma Conservation Commission personnel. The data produced has also been disseminated at state conferences such as the Ozark Summit in Tahlequah, OK where attendees discussed climate change mitigation and adaption strategies in Oklahoma. The data was also presented at the ASA-CSSA-SSSA International Annual Meeting. PARTICIPANTS: The following undergraduate students work on this project: Austin Hudson, Dept. of Plant and Soil Sciences Andrew Whitaker, Dept. of Plant and Soil Sciences Clayton Elder, Environmental Science Amanda Rauh, Natural Resources and Ecology Management The following graduate student work on this project: Tracy Wilson, Dept. of Plant and Soil Sciences These students assist with research activities associated with this project. Tracy Wilson's research project focuses on the assessment of carbon sequestration in cellulosic bioenergy production systems. The following faculty members in the Department of Plant and Soil Sciences are collaborators in this project: Chad Godsey, Assistant Professor Tyson Ochsner, Assistant Professor Gopal Kakani, Assistant Professor The following Oklahoma Conservation Commission personnel are collaborators in this project: Stacy Hansen, Oklahoma Carbon Program, Director. TARGET AUDIENCES: Government agency personnel Carbon credit aggregators Landowners Agricultural producers Efforts will be made to utilize the information gather from this project in improve their knowledge about the management required to sequester soil organic carbon and the rate at which different production systems sequester soil organic carbon. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The results collected from this project have demonstrated that the carbon content of Oklahoma soils varies widely as a function of soil type and environmental conditions. This variation along with the large mass of carbon found in surface soils make it difficult to accurately assess the impacts of the multiple variables that influence carbon sequestration in a short period of time. However, continued research efforts will provide an improved understanding of carbon cycling in Oklahoma soils such that sound recommendations can be made to optimize carbon sequestration estimates and ensure the quality of carbon credits generated in Oklahoma.

Publications

• Wilson, T.M., and J. Warren. 2010. Changes in estimates of carbon stocks in a high shrink/swell soil. In Agronomy abstracts CD-ROM. ASA, Madison, WI.
• Warren, J., and C. Godsey. 2010. Summary of the soil carbon sequestration assessment program. CR-2265. Oklahoma Cooperative Extension Service, Oklahoma State University, Stillwater, OK. Oct.