Characterizing Soil Health and Yield Under Conservation Practices in Soybean and Grain Production Systems
Sustainable Production
DiseaseField management Pest
Lead Principal Investigator:
Lisa Fultz, Louisiana State University AgCenter
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
Introducing a change in agronomic practices requires a soil system restart. With conservation practices, that reset often results in lower crop yield as the soil microbes adjust. Over time, those practices change soil characteristics, improving soil quality and crop yield. Thanks to years of research the team is analyzing those long-term changes in soil systems to better understand the effects of conservation practices like incorporating cover crops and reducing tillage. Plus, they are leveraging that soy checkoff support into additional funding for her practical research.
Key Beneficiaries:
#agronomists, #Extension agents, #farmers
Unique Keywords:
#agronomy, #cover crops, #no-till
Information And Results
Project Summary

Practices which improve soil and water quality, like increasing soil organic matter which also improves soil stability, become more desirable when coupled with the increased consumer interest in sustainable products. These improvements come with some cost. For example, the use of conservation tillage increased soil organic matter content by 20% over 5-years, with a 35% increase measured when conservation tillage was paired with cover crops in an ongoing study at the Macon Ridge Research Station. These increases in soil organic matter were linked to increased total soil N content, C, N, and S cycling enzyme activity, and inorganic N availability, ultimately decreasing N fertilizer requirements for corn production. However, these systems also experienced some yield decrease in the early of years of establishment, which may be unsustainable for most producers if yield recovery does not occur. This lag in recovery is often used to justify the need for long-term commitments to conservation practices, however, due to the nature of academic research (limited to 2-3 years), it is often difficult to obtain the data to support these statements. The availability of multiple long-term (>5 year) sites managed under conservation practices is a unique opportunity for data collection. Additionally, as more producers adopt these practices, it becomes possible to monitor these changes in large-scale production systems, which may differ from typical small plot research.

Regionally specific recommendations for species and seeding rate are needed to better address producers’ questions. As lower recommended seeding rates for cereal rye have already been established, data collected has also indicated a lower recommended seeding rate for most grass cover crops that will allow for adequate biomass production at a lower cost to the producer. However, Louisiana’s unique climate coupled with highly variable weather patterns has produced many questions on the best methods for managing cover crops once they have been established. While surface coverage provides the best possible scenario for soil conservation, Louisiana’s warmer winters, which allows for continued cover crop growth, may also support populations of pests and diseases for subsequent cash crops. Identifying the opportune window to balance soil conservation with crop production requires a broader understanding how the various components of each system operate. For this reason, we propose to include additional assessments, specifically pest and weed measurements, of production conditions over the growing season.

Project Objectives

Objective 1: Assess long-term conservation management practices impacts on soil health in large-scale production-based systems to establish similarities and differences to data collected from existing small-plot research trials.

Objective 2: Finalize cover crop seeding rates for legume and grass species typically grown in Louisiana. Establish 2nd year of brassicas seeding rate trials.

Objective 3: Examine impacts of cover crop termination timing and methods on soybean and grain yields, insect populations, and weed suppression.

Project Deliverables

Progress Of Work

Final Project Results

Benefit To Soybean Farmers

Data will help farmers answer questions and make decisions as they incorporate less tillage and cover crops into their systems.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.