Cover Crop Options for 2015

There are many opportunities to include cover crops in the rotation. The goal is to keep the soil covered with at least 30% crop, cover crop or residue, 100% of the time. A second goal is to have living roots in the soil as much as possible. Research at University of Guelph, Ridgetown Campus has shown that planting a cover crop provides a benefit, even if the growth is limited. So consider the these options and find a way to reap the benefits of cover crops.

Interseeding into Corn

There is a fair bit of interest in interseeding cover crops into standing corn. Different seeding times have been tried - from the 5- to 6 leaf stage of corn, to the tassel stage, to when the canopy begins to open up late summer or early fall. The most success in Ontario has been with seeding annual ryegrass and/or a clover at the 5 to 6 leaf stage of corn. Some growers have developed equipment to plant the cover crop or to move some soil after broadcasting the seed. Most broadcast the seed. Ryegrass seeding rates are generally 15 to 25 lbs/ acre. A rule of thumb for broadcasting cover crop seed is to add 20% to the drilled in rate.

It is important to think about the herbicide program when planning to interseed into corn. Table 1 lists herbicides that can reduce the success of the cover crop.

Table 1: Potential for injury to ryegrass and clover cover crop interseeded in corn.

Herbicide Annual ryegrass Clover
Converge XT Safe injured
Callisto Some injury - some stand reduction injured **
Engarde Some injury - some stand reduction injured **
Integrity - Set up rate Safe Not injured
Integrity - full rate Injury - stand reduction Some injury
Primextra Injury - stand reduction Some injury
Lumax Injury - stand reduction ** injured **
Treflan/Prowl Injury - some stand reduction * Some injury
Focus Injury - stand reduction ** Slightly injured
Frontier Marksman Injury - some stand reduction * Some injury

(*) Indicates severity of damage, more * = more damage
Source: Dr. Darren Robinson, University of Guelph, Ridgetown Campus, project funded under GF2

Some growers have interseeded cereal rye at 60 lbs/ac into corn as the crop begins to mature or even after harvest. They have achieved enough growth late fall and early spring to provide some benefit.

Cover Crops Following Cereals and Late Summer Harvested Crops

"Cover Crops Following Cereals and Late Summer Harvested Crops" has more information on cover crop options in this time frame.

Cover Crop Options in Soybeans

When winter wheat as a crop is not an option after soybeans, consider seeding a winter cereal as a cover crop. The most common option is rye, but any winter cereal will do such as wheat, barley or triticale. Broadcast 60 lbs/ac at 10% leaf drop, or drill it in immediately following harvest.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca