Principal Investigator: M. Scott Wells
Organization: University of Minnesota, Department of Agronomy and Plant Genetics
Sponsor: Clean Water Fund
Award Amount: $243,910
Start Date: 4/29/2014 | End Date: 6/30/2017
Project Manager: Heidi Peterson
Publication: View in ACSESS Digital Library "Establishment and Function of Cover Crops Interseeded into Corn" January 2018
Due to a short fall season in Minnesota, establishing cover crops in corn-based cropping systems is a challenge. Most Minnesota farmers harvest corn in mid-October, but best management practices (BMPs) recommend planting cover crops six-to-eight weeks prior to a killing frost, well before corn harvest. Aerial seeding between August and mid-September has mixed results due to soil moisture, improper seed placement and vulnerability to animal/insect predation. More research is needed to improve cover crop establishment in corn-based cover cropping systems.
For this project, researchers will establish cover crops when corn is at the V7 to V8 growth stage (approximately 38 inches tall, 30-40 days after planting). At that point there is good soil moisture and also cover crops remain in a vegetative stage throughout the growing season and have a higher likelihood of surviving winter. Applying cover crop seed much before the V7 to V8 stage can lead to increased cover crop competition with the corn.
Image from Purdue University
New Equipment and Technology
Broadcasting cover crop seeds (applying them on top of the soil surface) into corn is the simplest seeding method. However, broadcast seeding often produces inconsistent results. Without soil disturbance to incorporate the seed and achieve adequate seed-to-soil contact, cover crop establishment can be low if rainfall does not occur soon after seeding.
New technologies have been developed to allow for earlier planting and to capitalize on the benefits of broadcast inter-seeding. For example farmers have modified high-boy seeders to be capable of planting directly into growing corn.
The need for improved cover crop establishment has prompted other technologies and research. Pennsylvania State University developed a 3-in-1 inter-seeder capable of direct-drilling cover crop seed in corn as late as the V8 stage, while simultaneously applying fertilizers and herbicides. Combining field activity is cost effective. Also, applying nitrogen during the growing season can reduce the potential for nitrogen losses.
Research results will target agricultural professionals, farmers, state agencies and environmental groups to include:
Events will include:
Education and outreach topics will focus on: Cover crop inter-seeding technologies and subsequent impacts on water quality; explanation of best management practices; agronomic and environmental risk assessments for various management practices; economic projections for cover crop inter-seeding technologies into current com cropping systems.
Supervisor, Clean Water Technical Assistance Unit