Kyle Schminke of Shellsburg, Iowa plants corn and soybeans into a green wheat cover with a modified 40-foot drill. This allows him to plant into a 20-inch space with cover crops growing on either side. “I think when it is still green out there, the ground is a better seed bed than when planting after termination,” says Kyle. 

Planting and Termination: Kyle allows the wheat to get to about 12-15 inches tall ahead of corn and about knee high ahead of soybeans. After planting corn or soybeans green, Kyle aims to terminate his cover crop with Round-Up a week to 10 days after planting. 

Moisture and N tie-up: Cover crops like wheat or rye absorb a lot of moisture when growing in the spring. It is important that moisture is not being diverted away from cash crops at planting. “We look at the available moisture in the soil and the forecast, then make our plan to avoid losing moisture,” says Kyle. If conditions appear too dry ahead of planting Kyle will plan to terminate his wheat earlier. Another hurdle when planting green is avoiding nitrogen tie-up. Kyle applies 32% N to the seed row after planting, but before emergence, to mitigate N tie-up. 

Skip-rows: Leaving a skip-row or gap-row in the cover crop is a management strategy when planting green to avoid too much competition between the green cover and emerging seedlings. “I believe you have to have some space within the cover crop for the seed row. Otherwise you’re going to have to terminate the cover a lot sooner to prevent competition,” cautions Kyle.

Four other assistance programs share this April 8 deadline. Find out more on the NRCS website. 

“Should I plant corn into a green, living cereal rye cover crop? Or should I wait until the cereal rye cover crop is brown and dead before planting corn?” Just as the robins and crocuses reappear each spring, so too do these questions among corn farmers who use cover crops.

Research by PFI farmers and university scientists over the past decade provides some insights.

In this video from PFI’s 2022 annual conference Will Cannon and Andy Linder discuss best practices for planting green.

Will and Andy share their ideal scenarios for cover crop growth and weather patterns when planting green. Hear strategies to set up favorable conditions by using less aggressive cover crops or prioritizing early corn planting.

See results from three 2020 on-farm trials in this PFI research report.

Sam Bennett, Tim Sieren, and Jon Bakehouse, compared cereal rye biomass, soybean stand counts and soybean yield between strips in which a rye cover crop was terminated near the date of planting soybean (near-plant termination) and strips in which rye termination was delayed until 16 to 52 days after planting (delayed termination).

PFI Cooperators Dick Sloan and Wade Dooley conducted research trials to assess termination dates of cover crops near the corn planting date.

The objective of this research project was to determine if terminating a cover crop before accumulating 3,000 pounds per acre of biomass would allow corn to be planted sooner than 10 days after termination (DAT) without sacrificing yield or increasing disease incidence.

April 6: Webinar - Rotational No-Till Series- Part 1

April 6-8: Conference - Conservation Drainage Network Annual Meeting

April 13: Webinar - Topic TBA

April 20: Webinar - Rotational No-Till Series- Part 2

April 20: Webinar - Topic TBA

April 27: Webinar - Topic TBA

April 27: Virtual Event - Cover Crop Specialist Call

April 27: Workshop - Agronomy in the Field

Want to host a cover crop meet up? Are you planning or hosting a cover crop event? Contact taylor@practicalfarmers.org to plan something or to promote your event.

Send us your cover crop poll ideas! We want to know what YOU want to know. Reply to this email with your ideas for the next poll.

At what stage do you terminate your rye for soybean planting?