lacrosseseed.com | Copyright © 2018 La Crosse Seed, All rights reserved.

About The Dirt The Dirt is a periodic email series with timely cover crop tips from the agronomic experts at Soil First and La Crosse Seed. If you have a question you’d like us to answer, contact us: info@laxseed.com or 800.356.7333

It’s that time of year again, when growers who were unable to plant cover crops the previous fall consider an alternative method of incorporating cover crops into their operation - interseeding into standing corn.

We’ve participated in interseeding conversations the last 4-5 years, and continue to learn more each season. Planting what’s often referred to as a “companion crop” (or “relay crop”) includes several challenges, however it seems every year a new set of growers find the right combination of seed, equipment and planning to make it work. Below are recommendations to help increase your chances of interseeding success:

TIPS FOR INTERSEEDING COVER CROPS ON YOUR FARM

lacrosseseed.com | Copyright © 2018 La Crosse Seed, All rights reserved.

About The Dirt The Dirt is a periodic email series with timely cover crop tips from the agronomic experts at Soil First and La Crosse Seed. If you have a question you’d like us to answer, contact us: info@laxseed.com or 800.356.7333

1. Determine objectives for adding a cover crop. This drives the decision on what species to use and how to make the system work best.

2. Start small with an area easy to manage and document. This may seem obvious, but it’s better to study acres that can be easily compared against a control (non-use), keeping all other factors constant.

3. Secure the right equipment. There are many options, but an offset drill or planter seems to work well, as we’ve noticed that a little soil disturbance can help. As strip tillage gains momentum, technology and equipment options are also increasing. As with many of the species we market, it’s better for seed to be IN the ground versus ON the ground.

• Remember, the goal is to get seeds to germinate quickly once planted, getting established before summer heat drives up in-row temperatures. Broadcast applicators can also work, especially if moisture is in the forecast or an irrigation event can be scheduled. If broadcast equipment will be used, remember to get the seed dropped below the corn whorl.

4. Consider pre-plant or recent early post-emerge herbicide treatments already applied. Understand the half-lives of all the chemistries in your operation and know that an early cover crop seeding might not function with many residual herbicides used today. Our website includes several resources that can help guide these decisions (search “herbicide” to view relevant options).

5. Timing is crucial. Some experts advise to interseed when corn reaches V3-V4, while others target V5-V6. Timing depends on many factors, from seed species to objectives to region and climate. University of Minnesota recommends waiting until later in the “critical weed free period”, or the time in the growing season when lack of weed control doesn’t necessarily impact corn yield.

This period can vary based on many factors, and many say that this critical period in corn is between V1-V10. If one considers that cover crops, like weeds, can compete with cash crops for nutrients, water and sunlight, research suggests waiting until V6-V7. This makes sense, but every field and system is unique and should be treated accordingly.

6. If the cover crop is competing too aggressively with the cash crop, be prepared to terminate the cover crop immediately. Stay on top of it, and monitor your cash crop closely. Tissue testing can be a logical addition to the management protocol.

7. 7. Be selective about the species used and make sure it will not be too competitive with the main crop (the most success we’ve seen has been with a legume like crimson or red clover). Use species that can tolerate shade and thrive in these environments. We’ve noticed that crimson clover and annual ryegrass perform best in low-light conditions followed by winter rye and several brassicas (like daikon radish).

It makes sense that legumes work well within standing grass crops, since the legume can “feed” the corn crop with additional N. However, this only works if the legume or other cover crop isn’t overly competitive with the cash crop. The value of a legume like crimson clover is its ability to grow and be vigorous (in a low-sun environment) while not hampering the growth of the corn or the corn’s ability to catch sunlight, nutrients and water.

Please share your findings with us, and let us know if interseeding is something that might be in play on

the acres you manage. We’re always learning, and the more we discover today, the more agronomic

insights we have tomorrow!