2018
Cover Crop Demos
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Contributor/Checkoff:
North Carolina Soybean Producers Association
Category:
Sustainable Production
Keywords:
AgricultureField management
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Katherine Drake Stowe, US Soybean Research Collaborative
Co-Principal Investigators:
Project Code:
P18-071
Contributing Organization (Checkoff):
North Carolina Soybean Producers Association
$12,500
Institution Funded:
North Carolina State University
$12,500
Brief Project Summary:

Systems using cover crops have improved soil microbial activity, increased nutrient cycling, mitigated against drought, reduced pests and soil erosion, and have lowered input costs over time. The primary goal of this project is to demonstrate to producers that a heavy cereal rye cover crop can be planted in a timely manner, allowed to grow and accumulate biomass, and then be terminated and rolled without using full tillage to provide important short-term benefits like weed control, major disruption of soil moisture conservation and insect suppression for the subsequent cotton or soybean crop.

Key Benefactors:
farmers, agronomists, extension agents

Information And Results
Project Deliverables

Final Project Results

Cover crop: When the cover crop was not fertilized, cover crop biomass ranged from 3,400 to 5,890 lb/acre across our experiment sites. Fertilizing the cover crop enhanced cover crop biomass production from 220 to 1,180 lb/acre, depending on experiment site. AU Robin is an early flowering crimson clover variety, and it produced hard seed prior to termination, which led to both summer and fall volunteer crimson clover growth. The preemergence herbicides applied at cotton planting did an excellent job controlling the summer volunteer crimson clover. Fall volunteer crimson clover appeared unaffected by herbicide use during the cotton season, and a full crimson clover stand was present at cotton harvest. This fall, volunteer crimson clover did not interfere with cotton harvest. Letting your crimson clover go to hard seed prior to termination can be used as a cost-saving mechanism for cover crop seeding.

Cotton emergence: Cotton emergence declined when cotton was planted directly into standing cover crop and when the residue managers were floated at cotton planting thereby, leaving the cover crop present in-row. When the cover crop was rolled and the residue managers were engaged at cotton planting, cotton emergence was similar to cotton planted into bare ground.

Soil temperature and moisture: Soil temperature was always reduced by the presence of a cover crop, regardless of cover crop residue management strategy. Reduced soil temperature could affect cotton emergence and intensify seedling diseases. Regardless of cover crop residue management strategy, the presence of a cover crop always enhanced soil moisture availability. We were especially surprised to see similar soil moisture conservation
benefits when cotton was planted into a standing cover crop compared to a rolled cover crop. These results indicate that producers that do not have a roller may be able to reap the soil moisture conservation benefits of a cover crop by planting into a standing cover crop.

Weed dynamics: Using herbicides in combination with the cover crop mulch provided excellent weed suppression. Concern has been expressed about preemergence herbicides binding up in cover crop residue and not reaching the soil; however, preemergence herbicides applied to our cover crop mulch in this study provided great control. Further work is merited to determine which herbicides may be more prone to tie-up in cover crop residues. The cover crop biomass levels achieved in this study did not provide adequate weed control in the absence of herbicide use.

Cotton yield: Cover crop residue management did not affect cotton lint yield at four of the five experiment sites in this study. Irrigation was used in these studies when moisture was limited, which may explain lack of yield differences between a cover crop and no cover crop despite enhanced soil

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.