Project Details:

Economic and environmental impact of dual-use cover crop species in Tennessee no-till soybean/corn rotations

Parent Project: This is the first year of this project.
Checkoff Organization:Tennessee Soybean Promotion Board
Organization Project Code:19-154-P
Project Year:2019
Lead Principal Investigator:Virginia Sykes (University of Tennessee-Institute of Agriculture)
Co-Principal Investigators:

Contributing Organizations

Funding Institutions

Information and Results

Click a section heading to display its contents.

Project Summary

Cover crops offer many ecological benefits, including improvements to soil health and suppression of hard to control weed species. However, the magnitude of these returns is dependent on adaptation regionally and to rotation systems which vary in establishment/ termination timing. Cover crops may also provide additional economic returns through dual-use as both a cover and a forage, though it is unclear if this practice reduces ecological benefits. The objectives of this study are to 1) Assess regional adaption of 17 cover crop species to East, Middle, and West Tennessee under two establishment/ termination timings and 2) Quantify economic and ecological impacts in a conventional cover crop system compared with a dual-use cover crop/forage system.

This study builds on an initial year of data collected in 2017/2018 through funding from the United Soybean Board. Results from year 1 showed significant differences in species adaptation and ecological benefits between early and late planted cover crops. While an increase in cash crop yield was not observed, protein did differ by preceding cover crop species and harvest type (dual-use vs. conv.). Dual-use plots produced high quality forage without a significant reduction in ecological benefits suggesting a dual-use system may offer further economic incentive to cover cropping. Because year to year environmental variation, particularly difference in temperature extremes, can have a significant impact on species adaptation, a second year of data collection is essential.

Project Objectives

This study will utilize existing plots established at Tennessee AgResearch and Education Centers in Knoxville, Spring Hill, and Milan. Experimental design is a crossover randomized complete block design with three replications of 10 ft x 25 ft plots arranged in an 18 x 2 x 2 factorial of the following treatments:
- Species: no cover control, cereal rye, wheat, oat triticale, barley, red clover, crimson clover, arrowleaf clover, berseem clover, sunn hemp, hairy vetch, woolypod vetch, common vetch, winter pea, forage radish, canola, turnip
- Timing: Short season: est following soybeans (mid-Oct), term. prior to corn (early-April); Long season: est. following corn (mid-Sept.), term. Prior to soybean (mid-April)
- Management: 1) conventional: cover terminated chemically prior to cash crop establishment; 2) dual-use: cover harvested as a forage and terminated chemically prior to cash crop establishment.

Project Deliverables

Cover crop seeding rates and corn and soybean fertility will follow UT extension guidelines. Fertility rates will be based on soil test results from the fallow (no cover) plots and will be applied equally to all plots in order to gauge potential nitrogen credits from each species.

Findings from this project will be presented throughout regional meetings, field days, blog posts, and Extension agent in-service training events. Co-PIs will work together to develop cover crop species Extension fact sheets which will include information on regional adaptation, economic benefits, and ecological impacts. A web-based application will also be developed to further simplify producer utilization of best practices identified in this study. Users will be allowed to input various cover crop/ cash crop combinations and management practices (e.g. dual use vs. single use, short season vs. long season) and an algorithm will be used to populate data on appropriate cover crop management practices, soil health benefits, potential weed and insect issues, nutrient benefits, and potential yield and economic return of cover crop species grown in Tennessee and the mid-South.

Progress of Work

Final Project Results

Updated February 3, 2021:

View uploaded report Word file

Benefit to Soybean Farmers

Performance Metrics

Project Years