Tennessee - SARE Southern

Last Updated on November 10, 2022 by Danielle McDonald

Increasing Cropping Systems Resilience with Cover Crops

The preliminary data from a three-year Southern Sustainable Agriculture Research and Education Grant found that cover crops can help to buffer extreme soil temperature changes. They also provide a multitude of other benefits, including enhanced soil health, lessened soil erosion, and increased capacity to hold water. These findings could help improve the resilience of cropping systems when facing extreme weather changes.

Researchers from Middle Tennessee State University, Auburn University, and University of Kentucky are studying the effects of cover crops on soil heat capacity and thermal properties, and how these factors influence crop productivity. Other indicators of soil health were also examined, such as water retention, bulk density, pore sizes distribution, organic carbon, soil pH, and microbial biomass.

Samuel Haruna stated that rising temperatures could affect soil ecosystem services, crop productivity, and agricultural and environmental sustainability.

An assistant professor in soil science from Middle Tennessee State University and the project’s principal investigator stated, “Therefore, it is important to identify soil and crop management practices that are more adaptive to a changing climate.”

Two farmer fields in Tennessee contained two treatment options (cover crops vs. no cover crops) with three copies of each treatment. Both treatment plots had heat flux plates and thermal sensors installed. After cover crops were planted, soil temperature and water content sensors were also installed. Samples of soil were taken before, during, and after cover crops were planted.

The results showed that soil properties were similar between cover crop and no cover crop management before cover crops were planted. However, they were substantially different before cover crop termination.

Bulk density, for example, was 18% higher when there was no cover crop management than it was under the cover crop treatment prior to termination. Haruna stated that this was due to cover crop roots opening up soil pores, and also due to higher soil organic carbon under cover crop management (organic carbon was 14% higher under cover crop management than with no cover crop management).

Haruna stated that, “No cover crop management significantly increases thermal conductivity and thermal diffusivity. Further, as a result of higher soil organic carbon and water content, volumetric heat capacity was 21% and 14% higher at saturation and field capacity under cover crop compared with no cover crop management. This demonstrates that cover crop management can buffer against significant heat transfer within the soil, helping to keep the soil temperature stable for longer periods.”

Another study found that water infiltration was 52% higher before cover crop termination, and 68% higher two months after termination. This is compared to the results for crops with no cover crop treatments. This indicates that soil water infiltration can be increased by cover crops, and may persist even after the cover crop is removed.

Moreover, those under cover crops had a numerically higher saturated hydraulic conductivity than those with no cover crops management. This shows that cover crops can be used to reduce surface runoff and soil losses, and increase water infiltration, and storage. Thus, potentially improving crop productivity.

SARE in Tennessee

The Tennessee SARE program is made possible through a collaboration between the University of Tennessee Institute of Agriculture and Tennessee State University Cooperative Extension. Their collaboration enables them to create a program to improve the state’s environmental, social, and economic sustainability through education and research. Tennessee SARE works with producers, researchers, extension faculty, and community organizations to research and implement the top science-based practices available in every area of Tennessee’s agriculture system. In addition to research, SARE is committed to providing education in sustainable agriculture through a variety of training each year.

You can also read more about Farm Certifications – SARE Southern.

Tennessee Impacts

$2.7 million in funding since 1988
71 projects funded since 1988

You can also read about the South Carolina – SARE Southern and the Texas – SARE Southern.

Professional Development Program

In each state, agricultural educators work directly alongside farmers and ranchers to promote sustainable agriculture production and marketing. SARE state agricultural coordinators offer support in sustainable agriculture education and outreach strategies through a program called “The Professional Development Program” (PDP).

Fellows Program

The Sustainable Agriculture Fellows Program is offered by SARE and NACAA. It enhances Cooperative Extension staff’s knowledge of sustainable agriculture and gives them broad-based national exposure to unique and successful sustainable agriculture programs.

State Contacts

SARE State Coordinators play a vital role in expanding sustainable agriculture training for Extension, NRCS and other agricultural professionals. This will help producers transition to a more sustainable farming system.

Jason de Koff

Extension Associate Professor

Tennessee State University

Email | (615) 963-4929

Troy Dugger

TN SARE Program Assistant

University of Tennessee

Email | (931) 486-2777

Rob Holland

Director