SHELBYVILLE, Ind. — With more attention being paid to the implementation of cover crops, The Land contacted Anna Morrow for her expertise on the subject. Morrow is the Program Manager at Midwest Cover Crops Council. Founded in 2006, MCCC works with farmers, universities, federal and state agencies, and other individuals and organizations to facilitate the widespread adoption of cover crops across the Midwest. The Council serves farmers in Minnesota and Iowa as well as a number of other Midwestern states and Ontario.
The Land talked with Morrow about the organization’s work getting cover crops adopted across the Midwest.
The Land: You're in Indiana. Are cover crop strategies in Indiana relevant to farming with cover crops in Minnesota and Iowa?
Morrow: Cover crop principles are basically the same throughout the Midwest. But species, growing seasons, and pest concerns vary across the region. We like to organize our recommendations by state or province to better work with our partners. We work closely with Midwest land grant universities and like to take advantage of the synergy of working together along with other government and industry partners.
The Land: Your website has state-by-state cover crop recipe recommendations. MCCC is recommending oats or a mixture of oats and radishes in Minnesota or Iowa when going from soybeans to corn. Why oats and radishes?
Morrow: Most of our cover crop recipes and guidance generally recommend oats or oats with radish after soybean and before corn. This is a good low-risk entry point for becoming more comfortable with cover crops. Typically we have a little more growing season left after soybean harvest, so that’s a better time for cover crops that will winter kill like oats and radish. We like winter killed covers ahead of corn for beginners because we don’t have the risk of nitrogen tie-up that we have with an actively growing cover in the spring like cereal rye; and, additionally, there is basically no spring management.
The reason some states recommend radish while others don’t is that radishes are more sensitive to cold weather and just don’t perform well without adequate heat. So northern states may not recommend radishes.
The Land: In Iowa and Minnesota, MCCC recommends using a cereal rye cover crop following corn and going to soybeans. Why a cereal rye and not oats?
Morrow: We like cereal rye before soybeans because it’s very hardy and can handle late planting after corn harvest. It also makes a great cover to suppress weeds and provide some mulch for the beans into the growing season. Soybeans don’t really mind the nitrogen tie-up which typically comes with a cereal rye cover, and so it’s a good choice for beginners. As we state on all our recipes, they are intended to provide a starting point for farmers who are new to growing cover crops.
The Land: You’re emphasizing that these cover crops are a good starting point for beginners. Why the focus on beginners?
Morrow: MCCC tends to focus on farmers new to cover crops with resources such as our recipes and our cover crop selector tool that uses county-specific weather data. Since the majority of farmers are in this category, we feel like this is the most impactful. More experienced cover crop farmers would likely find our network of experts from industry, academia, and other farmers more valuable. Once farmers have a little experience, they’re usually more comfortable tweaking cover crop management for their specific situation.
The Land: I’m farming vegetables on a small scale. We’ve historically planted oats following early onion and potato harvests. This year we planted peas and sunflowers with the thinking that diversity was a good thing. Do you have thoughts on the value of diversity in cover crops?
Morrow: Diversity is valuable as long as you can manage it without putting your cash crop at risk. For example, radishes are recommended in Minnesota after a canning crop because there is more time to get a benefit from their growth as compared to after soybeans. Radishes are a great way to add some diversity to your crop rotation and sequester nutrients. They are also useful in reducing soil compaction which is a big concern after canning crop harvest.
The mixture that you used is also a good mix in terms of diversity, because it has three different classes of cover crop species.
The Land: Would you recommend seeding any of your recipes before harvest?
Morrow: Oats, radish, and cereal rye can be seeded before harvest, and this is a great way to extend the growing season for your cover crop. It also allows you to use some species that would otherwise not have enough time to establish before a killing frost if they were seeded after harvest.
Some farmers are doing some early inter-seeding of cover crops before the corn canopies. Timing, species selection, and management are more advanced for this practice and are very regionally specific.
The Land: What herbicides are generally used for termination of cereal rye? Are there any carry over risks? I’m an organic farmer. Are you aware of successful mechanical termination with equipment like crimpers?
Morrow: Generally speaking, for cover crop termination a routine burn-down herbicide will kill an actively growing cover crop in the spring. Where we need to be careful is when residual herbicides are used in season and a cover crop is planned for later that fall.
Lots of farmers are having success using a roller crimper for termination of a few covers like cereal rye. This is an intensive management practice which needs to be very specific. Roller crimping needs to be done at antithesis or when the rye begins to shed pollen. You want to be sure to use a stated variety, so that you know it will reach this growth stage uniformly and timely enough for cash crop planting.
Beginning, as well as experienced cover crop farmers, can learn more about MCCC’s state-by-state cover crop recipes and their management by visiting their website at www.mccc.msu.edu. The website also has extensive resources on cover crop species including brassicas, grasses, legumes, and non-legumes such as sunflowers and buckwheat.