Minnesota

Midwest Cover Crops Council (MCCC-131)  


This publication is intended to provide a starting point for farmers who are new to growing cover crops. With experience, farmers may fine-tune the use of cover crops for their systems.

Introduction

This recipe provides an introductory approach for integrating a cereal rye cover crop into a corn silage–soybean rotation.

Planning and Preparation
  • Planning—Educate yourself. Go to field days, learn from farmers who are currently planting cover crops, read about cover crops, check out University of Minnesota cover crop research, and work with your local Natural Resources Conservation Service (NRCS) and Soil and Water Conservation District. Start small and be timely. Consult with your crop insurance representative to ensure planned practices will not affect your insurance coverage.
  • Corn hybrid and planting—If possible, plant the preceding corn silage crop early and use a hybrid adapted to your location.
  • Residual corn herbicides—Manage for optimal weed control. Apply a preemergence herbicide to help control troublesome weeds such as waterhemp, which emerges over a long period of time and late in the season, or weeds that are resistant to key postemergence herbicides. Cereal rye can tolerate most residual corn herbicides applied earlier in the season, but if the rye will be grazed or used for forage, you must follow rotational restrictions listed on the label of any applied herbicides. (See Managing Risk When Using Herbicides).
  • Seed purchase—Order cereal rye seed early from a reputable source. Use good-quality tagged seed that has been cleaned and tested for germination and weed seed contamination. Named varieties can produce greater growth and have more predictable development, but they are usually more expensive than VNS (variety not stated) seed. Utilize University of Minnesota field crop variety trial results for winter rye in variety selection, and consider forage quality if you intend to harvest the cereal rye for forage.
Fall Work
  • Corn silage harvest—Prioritize fields where cereal rye is to be planted.
  • Tillage, manure, fertilizer, and lime—Generally, cover crops are more successful in no-tillage or strip-tillage systems. For best rye establishment, any manure, fertilizer, or lime should be injected, subsurface-banded, or surface-applied and incorporated before planting the cover crop. Manure can be injected with a low-disturbance applicator after the cereal rye is seeded, preferably after the cereal rye has reached 4 inches in height, although the cover crop may be damaged.
  • Timing of planting—Ideally, plant cereal rye by mid-September and as soon as possible after corn silage harvest to optimize biomass production. Try to time seeding before a rain.
  • Seeding rate—If drilling cereal rye (preferred for best establishment), use a minimum seeding rate of 55 lbs./acre of pure live seed (PLS). If broadcasting without incorporation, increase the rate to a minimum of 83 lbs./acre of PLS. Ensure that your seeding rate complies with any cost-share standards from a funding agency, if applicable. Consider increasing the seeding rate to increase forage yield.
  • Planting method—Drill seed to a depth of 0.75–1.50 inches or broadcast with shallow incorporation. Aerial seeding into standing corn once corn reaches the R5 (dent) stage is another option, but this carries more risk of poor establishment than drilling.
Figure 1. This cereal rye cover crop, shown in May, was seeded
the previous fall after corn silage harvest at the University of
Minnesota Southern Research and Outreach Center in Waseca.
(Lizabeth Stahl)
Spring Work
  • Termination timing—Terminate cereal rye in the spring when plants are actively growing and are no more than 12 inches tall. Terminating cereal rye at least 10 days prior to planting is a standard recommendation, especially under dry/drought conditions. Terminating at or just before planting will allow for more cover crop growth, but this practice carries more risk. Cereal rye can grow quickly in warm weather and be more difficult to control once it reaches the boot stage or is taller than 18 inches. Consult your crop insurance agent and check USDA-NRCS Cover Crop Termination Guidelines to ensure you are in compliance with rules on termination timing.
  • Termination herbicide—Cereal rye can be terminated with a full rate of glyphosate (minimum of 1 lb. acid equivalent/acre) after dormancy breaks in the spring. Termination is most effective and rapid when cereal rye is actively growing, applications are made on a sunny day at least four hours prior to sunset, and air temperatures are >60°F during the day and >40°F at night. Rye sprayed past the boot stage or during colder weather can be more difficult to kill, may require higher glyphosate rates, or will die more slowly.
  • Soybean planting—Most modern planters and drills are fully capable of planting soybeans into a dead or dying cereal rye cover crop. If cereal rye was drilled, planting soybean between rye rows is ideal. If cereal rye termination is delayed, it may be better to plant into standing green plants versus large plants that are dead or dying and that have fallen onto the soil surface, forming a thick mat of residue. Check planting depth and seed furrow closure in case any planter adjustments are needed.
  • Scouting after planting—Scout for soybean emergence, population, insect pests, and weeds. Substantial rye residue may delay weed emergence, ultimately delaying postemergence herbicide application.
Resources

Cover Crop Selector Tool — available from Midwest Cover Crops Council

University of Minnesota Extension Cover Crops website

USDA-NRCS Cover Crop Termination Guidelines (version 4: June 2019)

Minnesota Field Crop Variety Trials (University of Minnesota)

Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean (University of Minnesota Extension)

Spring Management of Cover Crops (University of Minnesota Extension)

Authors

Lizabeth Stahl, Anna Cates, and Axel Garcia y Garcia, University of Minnesota Extension (Note: This publication was adapted with consent from MCCC under a joint project to produce customized introductory guidance about cover crops for all member states/provinces.)

Reviewers and Contributors

Chryseis Modderman and Troy Salzer, University of Minnesota Extension; and Nathan Weise, East Otter Tail SWCD

The Midwest Cover Crops Council (www.midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the U.S. Midwest and Ontario by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by McKnight Foundation.

  September 2022 The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. ©2021 by MCCC. All rights reserved.

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Midwest Cover Crops Council (MCCC-130)


This publication is intended to provide a starting point for farmers who are new to growing cover crops. With experience, farmers may fine-tune the use of cover crops for their systems.

Introduction

This recipe provides an introductory approach for integrating a cereal rye cover crop after corn silage harvest and before corn for grain or silage.

Planning and Preparation
  • Planning—Educate yourself. Go to field days, learn from farmers who are currently planting cover crops, read about cover crops, check out University of Minnesota cover crop research, and work with your local Natural Resources Conservation Service (NRCS) and Soil and Water Conservation District. Start small and be timely. Consult with your crop insurance representative to ensure planned practices will not affect your insurance coverage.
  • Corn hybrid and planting—If possible, plant the preceding corn silage crop early and use a hybrid adapted to your location.
  • Residual corn herbicides—Manage for optimal weed control. Apply a preemergence herbicide to help control troublesome weeds such as waterhemp, which emerges over a long period of time and late in the season, or weeds that are resistant to key postemergence herbicides. Cereal rye can tolerate most residual corn herbicides applied earlier in the season, but if the rye will be grazed or used for forage, you must follow rotational restrictions listed on the label of any applied herbicides. (See Managing Risk When Using Herbicides)
  • Seed purchase—Order cereal rye seed early from a reputable source. Use good-quality tagged seed that has been cleaned and tested for germination and weed seed contamination. Named varieties can produce greater growth and have more predictable development, but they are usually more expensive than VNS (variety not stated) seed. Utilize University of Minnesota field crop variety trial results for winter rye in variety selection, and consider forage quality if you intend to harvest the cereal rye for forage.
Fall Work
  • Corn silage harvest—Prioritize fields where cereal rye is to be planted.
  • Tillage, manure, fertilizer, and lime—Generally, cover crops are more successful in no-tillage or strip-tillage systems. For best rye establishment, any manure, fertilizer, or lime should be injected, subsurface-banded, or surface-applied and incorporated before planting the cover crop. Manure can be injected with a low-disturbance applicator after the cereal rye is seeded, preferably after the cereal rye has reached at least 4 inches in height, although the cover crop may be damaged.
  • Timing of planting—Ideally, plant cereal rye by mid-September and as soon as possible after corn silage harvest to optimize biomass production. Try to time seeding before a rain.
  • Seeding rate—If drilling cereal rye (preferred method for best establishment), use a minimum seeding rate of 55 lbs./acre of pure live seed (PLS). If broadcasting without incorporation, increase the rate to a minimum of 83 lbs./acre of PLS. Ensure that your seeding rate complies with any cost-share standards from a funding agency, if applicable. Consider increasing the seeding rate to increase forage yield.
  • Planting method—Drill seed to a depth of 0.75–1.50 inches or broadcast with shallow incorporation. Aerial seeding once corn reaches the R5 (dent) stage is another option, but this carries more risk of poor establishment than drilling.
Figure 1. This photo was taken May 5, 2020, at the University of Minnesota Southern Research and Outreach Center in Waseca. Note the amount of biomass produced by a cereal rye cover crop seeded the previous fall after corn silage harvest (left) compared to where no cover crop was planted (right). (Lizabeth Stahl)
Spring Work
  • Termination timing—Terminate cereal rye in the spring when plants are actively growing and are no more than 12 inches tall or at least 10 days prior to planting corn—whichever comes first. Cereal rye can grow quickly in warm weather and be more difficult to control once it reaches the boot stage or is taller than 18 inches. Consult your crop insurance agent and check USDA-NRCS Cover Crop Termination Guidelines to ensure you are in compliance with rules on termination timing.
  • Termination herbicide—Cereal rye can be terminated with a full rate of glyphosate (minimum of 1 lb. acid equivalent/acre) after dormancy breaks in the spring. Termination is most effective and rapid when cereal rye is actively growing, applications are made on a sunny day at least four hours prior to sunset, and air temperatures are >60°F during the day and >40°F at night. Rye sprayed past the boot stage or during colder weather can be more difficult to kill, may require higher glyphosate rates, or will die more slowly.
  • Corn planting—Most modern planters are fully capable of planting corn into residue from a cereal rye cover crop. Row cleaner attachments may be beneficial. Check planting depth and seed furrow closure in case any planter adjustments are needed. A starter with N may be beneficial since decomposing rye can tie up some of the soil organic N that the emerging crop needs.
  • Scouting after planting—Scout for corn emergence, population, insect pests, and weeds. Substantial rye residue may delay weed emergence, ultimately delaying postemergence herbicide application.
Resources

Cover Crop Selector Tool — available from Midwest Cover Crops Council

University of Minnesota Extension Cover Crops website

USDA-NRCS Cover Crop Termination Guidelines (version 4: June 2019)

Minnesota Field Crop Variety Trials (University of Minnesota)

Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean (University of Minnesota Extension)

Spring Management of Cover Crops (University of Minnesota Extension)

Authors

Lizabeth Stahl, Anna Cates, and Axel Garcia y Garcia, University of Minnesota Extension (Note: This publication was adapted with consent from MCCC under a joint project to produce customized introductory guidance about cover crops for all member states/provinces.)

Reviewers and Contributors

Chryseis Modderman and Troy Salzer, University of Minnesota Extension; and Nathan Weise, East Otter Tail SWCD

The Midwest Cover Crops Council (www.midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the U.S. Midwest and Ontario by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by McKnight Foundation.

September 2022

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. ©2021 by MCCC. All rights reserved.

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Midwest Cover Crops Council (MCCC-126)


This publication is intended to provide a starting point for farmers who are new to growing cover crops. With experience, farmers may fine-tune the use of cover crops for their systems.

Introduction

A canning or processing crop such as green bean, sweet corn, or pea is harvested early or by midsummer and offers an excellent window to get adequate cover crop growth before any following crop. Cover crops following canning crops will protect soil from erosion and improve soil structure after heavy harvesting equipment is used to take off the canning crop. Some canning crops leave significant residual nitrogen (N) in the soil that is vulnerable to leaching, and a cover crop can retain that soil N for future crops. Since growers follow canning crops with any number of different rotations, a fast-growing species such as oats mixed with a light seeding of radish is a safe choice as both will winter-kill. With this combination, no spring termination is needed, and there is little chance of tying up N for the following year.

Planning and Preparation
  • Planning—Educate yourself. Go to field days, learn from farmers who are currently planting cover crops, read about cover crops, check out cover crop research results from local universities, and work with your local Natural Resources Conservation Service (NRCS) and Soil and Water Conservation District (SWCD). Identify your goals in planting a cover crop as these will drive many decisions. Start small, and choose a field that has low weed pressure to create the best conditions for success. Consult with your crop insurance representative to ensure planned practices will not affect your insurance coverage.
  • Canning crop management—Follow best management practices regarding fertility and weed management, and make sure to notify the canning company that you’re planning on a cover crop after a canning crop harvest.
  • Residual herbicides—Commonly used herbicides can negatively impact cover crop establishment, so check the history of herbicide application for your field. Oats can tolerate many preemergence and postemergence herbicides. However, if the oats/radish biomass is to be grazed or used for feed or forage, you must follow the rotational crop restrictions listed on the label of any applied herbicides. Rotational restrictions should be checked for herbicides used in the current and previous cropping season if the cover crop is to be grazed or used for feed or forage. (See Using Herbicides and Cover Crops in Corn and Soybean in Resources.)
  • Seed purchase—Order cover crop seed early from a reputable source. If you grow your own, get it tested for germination, purity, and weed seed. Named varieties can produce more growth and have more predictable development, but they are usually more expensive than VNS (variety not stated) seed. Use good quality seed that has been cleaned and tested for germination and weed seed contamination. Utilize local sources of seed as much as possible to help prevent the introduction of invasive noxious weeds such as Palmer amaranth.
  • Fertility or manure—Fall fertilizer incorporation could damage the cover crop and destroy any structure gained, so plan to apply any needed fertility after the cover crop has winter-killed. If manure will be applied in the fall, use low-disturbance injectors to minimize damage to the cover crop.
Summer/Fall Field Work
  • Timing of cover crop planting—After canning crop harvest, some light tillage may be necessary to create a seedbed for the cover crop. Using a leveling tool such as a vertical tillage bar with an air seeder on top allows for tilling and seeding the cover crop at the same time. Try to time seeding when rain is in the forecast, or if you use irrigation, you can water in the seed for reliable establishment.
  • Planting method—Drill the seed to a depth of 0.75 inch, or broadcast the seed with a shallow incorporation to less than 1 inch to allow for good seed-to-soil contact and enhanced establishment.
  • Seeding rate—For oats, a minimum seeding rate of 21 lbs./acre of pure live seed (PLS) is suggested when seed is drilled or incorporated. The seeding rate should be increased to a minimum of 45 lbs./acre of PLS if broadcast. For radish, the rate is 1.2 lbs./acre if drilled or incorporated, and 1.7 lbs./acre if broadcast. These rates are based on a mixture of 70% oats–30% radish. If another ratio is desired, rates should be adjusted using the Minnesota Cover Crop Design Tool (see Resources).
  • Tillage—No fall tillage is needed. The oat/radish residue will freeze, then decompose over the winter, and a cash crop such as field corn or soybeans can be no-tilled into the residue if you wish. While full-width tillage may be used in the spring, this will reduce soil structural improvements the cover crop provided over the winter.
  • Future considerations—An oat/radish mixture is promoted here as the entry-level cover crop mixture post-canning crop. In future years, you may consider grasses that survive the winter (e.g., winter rye or triticale) for spring erosion control or legumes (e.g., crimson clover, which winter-kills, or red clover, which survives the winter) to supply N to the next cash crop. However, both of these options will have separate considerations and management recommendations. Use the Cover Crop Selector Tool (see Resources), or visit with local representatives of NRCS or Extension for more specific information on seeding other species.
Figures 1 and 2: An oat-radish mixture planted Aug. 25 in Dakota County, MN, pictured on Sept. 24 (top) and on Oct. 14 (bottom). (Ashley Gallagher, Dakota SWCD)
Spring Work
  • Scouting—In the spring, scout the remaining cover crop residue, and note whether any oat seed that remained dormant over the winter begins to sprout in the spring. Any grass-target herbicide should take care of these escapes.
  • Cash crop planting—Most modern row planters are fully capable of planting corn or soybeans into residue from a dead oat/radish cover crop. Row cleaner attachments may be beneficial. Check planting depth and seed furrow closure shortly after beginning to plant in case any planter adjustments are needed, such as increasing down pressure to move through increased residue.
  • Scouting after planting—After planting, scout for emergence and population as well any insect, disease, or weed pressure.
Resources

University of Minnesota Extension Cover Crop website

Cover Crop Selector Tool —available from Midwest Cover Crops Council

Minnesota NRCS Resources, including Minnesota Cover Crop Design Tool

USDA-NRCS Cover Crop Termination Guidelines

Using Herbicides and Cover Crops in Corn and Soybean (University of Minnesota Extension)

Authors

Anna Cates, University of Minnesota Extension; Ashley Gallagher, Dakota Soil and Water Conservation District (Minnesota); Steve Lawler, Mower Soil and Water Conservation District (Minnesota); and Matt Ruark, University of Wisconsin–Madison Division of Extension

Reviewers and Contributors

Carl Rosen, University of Minnesota; Ken Schroeder and Dan Smith, University of Wisconsin–Madison Division of Extension; and Carissa Spencer, Minnesota NRCS

The Midwest Cover Crops Council (www.https://www.midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the Midwest by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by McKnight Foundation.

March 2021

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. ©2021 by MCCC. All rights reserved.

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Midwest Cover Crops Council (MCCC-114)


This publication is intended to provide a starting point for farmers who are new to growing cover crops. With experience, farmers may fine-tune the use of cover crops for their systems.

Introduction

Fitting cover crops into a corn-soybean rotation in Minnesota can be challenging due to weather constraints that result in a short growing season. Typically, there is little to no time to plant a cover crop and have appreciable growth after corn grain or soybean harvest. Planting a cover crop after small grains, a canning crop, or corn silage will often provide a wider window for establishment before a killing freeze. Since the dominant cropping system in Minnesota is the two-year corn-soybean rotation, this recipe provides an introductory approach for integrating a cereal rye cover crop into the corn year of the rotation.

Planning and Preparation
  • Planning—Educate yourself. Go to field days, learn from farmers who are currently planting cover crops, read about cover crops, check out University of Minnesota cover crop research, and work with your local Natural Resources Conservation Service (NRCS) and Soil and Water Conservation District. Start small, and choose a field that has low weed pressure to create the best conditions for success. Consult with your crop insurance representative to ensure planned practices will not affect your insurance coverage.
  • Corn planting—It may be useful to avoid late-maturity hybrids when planning to interseed a cover crop as this could allow an earlier planting date for the cover crop (if seeding in the fall) and more time for establishment prior to winter.
  • Residual herbicides—Manage for optimal weed control when adding a cover crop to your cropping system. Although commonly used herbicides in a corn-soybean rotation can negatively impact cover crop establishment, cereal rye can tolerate many of these herbicides. However, if the cereal rye is to be grazed or used for feed or forage, you must follow the rotational crop restrictions listed on the label of any applied herbicides. (In the Resources section, see Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean.)
  • Seed purchase—Order cover crop seed early from a reputable source. Use good-quality tagged seed that has been cleaned and tested for germination and weed seed contamination. Avoid planting seed of unknown origin and quality. Named varieties can produce greater growth and have more predictable development, but they are usually more expensive than VNS (variety not stated) seed.
Fall Work
  • Interseeding into corn—To maximize rye growth and soil protection, planting rye into standing corn around the R5 (dent) to R6 (physiological maturity) stage of corn is ideal. At this point, the corn canopy is starting to open, which will allow more sunlight to reach the ground to aid in cereal rye establishment. Broadcast seed by ground using a high-clearance seeder or by air using a plane or helicopter.
  • Planting after harvest—Alternatively, rye can be drilled after corn, although not too much growth will be attained. Plant the cereal rye to a recommended depth of 0.75 to 1.50 inches. Drilling allows for good seed-to-soil contact and enhanced establishment as compared to broadcasting seed. Adequate moisture after seeding will aid in successful establishment.
  • Seeding rate—For broadcasting cereal rye, use a minimum seeding rate of 83 lbs./acre of pure live seed (PLS). If drilling, use a minimum seeding rate of around 55 lbs./acre of PLS. If you receive funding from an agency or organization to plant a cover crop, double-check with them to ensure your seeding rate complies with any standards they might have.
  • Strip-tillage or no-tillage—It is easier to incorporate cover crops into a corn-soybean rotation when soybeans are no-tilled or strip-tillage is used. Full-width tillage in the fall will not allow for much cover crop growth, thus eliminating many of the potential benefits of planting a cover crop.
Figure 1: Cereal rye can grow quickly in warm conditions. Target termination before it reaches 12 inches in height or at least 10 days before planting soybean in the spring. (Axel Garcia y Garcia)
Figure 1: Cereal rye can grow quickly in warm conditions. Target termination before it reaches 12 inches in height or at least 10 days before planting soybean in the spring. (Axel Garcia y Garcia)
Spring Work
  • Scouting—In the spring, scout the cereal rye cover crop to determine how well it is growing. If rainfall is below normal or the long-term weather forecast calls for a drier season, monitor soil moisture in case earlier termination is needed.
  • Termination timing—Terminate the cereal rye in the spring when plants are actively growing and no more than 12 inches tall or at least 10 days prior to planting soybean—whichever comes first. Cereal rye can grow quickly in warm weather and be more difficult to control once it reaches the boot stage or is taller than 18 inches. Allowing at least 10 days between termination and planting will help ensure successful control. Check with your insurance agent to be sure you are in compliance with USDA-NRCS Cover Crop Termination Guidelines (see Resources).
  • Termination herbicide—Cereal rye can be easily terminated with a full rate of glyphosate (minimum of 1 lb. acid equivalent [ae]/acre) after dormancy breaks in the spring. Effectiveness and rapidity of termination improves if rye is rapidly growing, applications are made on a sunny day, and air temperatures are warmer (>60°F during the day and >40°F at night). Applications should be made during the day and at least four hours prior to sunset.
  • Soybean planting—It is usually best to no-till plant soybean into the dead or dying cereal rye cover crop. Most modern planters and drills are fully capable of planting soybean under these conditions. If wet or windy weather delays termination of the cereal rye prior to planting, it may be better to plant into standing green plants versus into large plants that are dead or dying and that have fallen onto the soil surface, forming a thick mat of residue. Check planting depth and seed furrow closure shortly after beginning to plant in case any planter adjustments are needed.
Resources

University of Minnesota Extension Cover Crops Website

Post Soybean, Going to Corn: Use Oats (Minnesota Cover Crop Recipe series, MCCC-115)—available from the Midwest Cover Crops Council

Cover Crop Selector Tool

USDA-NRCS Cover Crop Termination Guidelines

Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean (University of Minnesota Extension)

Cover Crops and Federal Crop Insurance (USDA Risk Management Agency Fact Sheet)

Authors

Lizabeth Stahl, University of Minnesota Extension; Anna Cates, University of Minnesota Extension; Axel Garcia y Garcia, University of Minnesota Extension; and M. Scott Wells, University of Minnesota Extension (Note: This publication was adapted with consent from MCCC under a joint project to produce customized introductory guidance about cover crops for all member states/provinces.)

Reviewers and Contributors

Marisol Berti, North Dakota State University; Frank Forcella, USDA-ARS; Eileen Kladivko, Purdue University; Anna Morrow, Midwest Cover Crops Council; and Bruce Potter, University of Minnesota Extension

The Midwest Cover Crops Council (www.https://www.midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the Midwest by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by McKnight Foundation.

October 2019

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. ©2019 by MCCC. All rights reserved.

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Midwest Cover Crops Council (MCCC-115)


This publication is intended to provide a starting point for farmers who are new to growing cover crops. With experience, farmers may fine-tune the use of cover crops for their systems.

Introduction

Using cover crops can be challenging in a corn-soybean rotation in Minnesota due to a short growing season. Typically, there is little to no time to plant a cover crop and have appreciable growth after corn grain or soybean harvest. Planting a cover crop after small grains, a canning crop, or corn silage will often provide a wider window for establishment before a killing freeze. In a corn-soybean rotation, it is easier to begin by planting a cover crop ahead of soybean and following corn, so consider starting with the companion recipe titled Post Corn, Going to Soybean: Use Cereal Rye (MCCC-114; see Resources).

However, cover crops that are planted post soybean and going to corn provide soil protection and organic matter inputs, so the following recipe provides a low-risk, introductory approach for this window. Oats were selected following soybean in a corn-soybean rotation because oats (1) are typically readily available and inexpensive, (2) tend to be more tolerant to many herbicides, and (3) winter-kill, which eliminates the need for a termination plan in the spring and reduces the risk of a green bridge for disease or insect pests to corn.

Planning and Preparation
  • Planning—Educate yourself. Go to field days, learn from farmers who are currently planting cover crops, read about cover crops, check out University of Minnesota cover crop research, and work with your local Natural Resources Conservation Service (NRCS) and Soil and Water Conservation District. Start small, and choose a field that has low weed pressure to help create the best conditions for success. Consult with your crop insurance representative to ensure planned practices will not impact your insurance coverage.
  • Soybean planting—If possible, plant the preceding soybean crop early and avoid varieties that are very full season for your area. One possible strategy is to use your earliest-maturity group soybeans on fields where you plan to seed a cover crop. For more information, see Soybean Variety Selection.
  • Residual herbicides—Manage for optimal weed control when adding a cover crop to your cropping system. Apply a preemergence herbicide to help control troublesome weeds such as waterhemp, which emerges over a long period of time and late in the season. Preemergence herbicides also aid in the management of weeds that are resistant to key postemergence herbicides. Oats are tolerant to many soybean residual herbicides, but if the oats are to be grazed or used for feed or forage, you must follow the rotational crop restrictions listed on the label of any applied herbicides. (In the Resources section, see Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean.)
  • Seed purchase—Order cover crop seed early from a reputable source. Use good-quality tagged seed that has been cleaned and tested for germination and weed seed contamination. Avoid planting seed of unknown origin and quality. Named varieties can produce greater growth and have more predictable development, but they are usually more expensive than VNS (variety not stated) seed.
Fall Work
  • Timing of cover crop planting—Given the limited time for cover crop establishment after harvest, interseeding a cover crop into standing soybean when leaves start to yellow and drop (around beginning maturity) is preferred. This should correspond to a seeding timing of late August to early September in most of Minnesota. Pay attention to the short-term weather forecast as rainfall after seeding is essential for establishment. Seeding the cover crop immediately after soybean harvest is also possible, particularly where soybeans were drilled, planted in narrow rows, or had extensively lodged. However, this timing may not provide enough time for adequate cover crop growth and development before a killing frost in the fall.
  • Planting method—Aerial seed with a plane or helicopter or broadcast seed with a ground-based vehicle into the standing soybean crop. Alternatively, if seeding after soybean harvest, drill to a depth of 0.50 to 1 inch or broadcast with shallow (<1 inch) incorporation.
  • Seeding rate—A seeding rate of 45 to 65 lbs./acre of pure live seed (PLS) is suggested when seed is broadcasted and not incorporated. A seeding rate of 30 to 45 lbs./acre of PLS is recommended when seed is drilled.
  • Soybean harvest—Harvest fields where the cover crop is to be planted as early as possible. This is not as critical when cover crops are seeded before harvest.
  • Tillage, fertility, or liming—It is generally easier to incorporate cover crops into a no-tillage or strip-tillage system. If full-width tillage is planned, it is best to delay this until after a killing frost to allow for maximum growth of the oat cover crop. If N fertilizer or manure will be injected in the fall, it is usually best to wait until after the cover crop has winter-killed. Use a low-disturbance applicator to minimize incorporation of surface residues.
Figure 1: These oats were seeded in the fall after soybean harvest in a no-tillage soybean/strip-tillage corn rotation. The field was strip-tilled after oat emergence. (Lizabeth Stahl)
Figure 1: These oats were seeded in the fall after soybean harvest in a no-tillage soybean/strip-tillage corn rotation. The field was strip-tilled after oat emergence. (Lizabeth Stahl)
Spring Work
  • Termination—Oats should winter-kill, so termination is not needed.
  • Corn planting—Most modern row planters are fully capable of planting corn into residue from soybean and an oat cover crop. Row cleaner attachments may be beneficial. Check planting depth and seed furrow closure shortly after beginning to plant in case any planter adjustments are needed.
  • Scouting after planting—As usual, scout for corn emergence, population, and insect pests after planting. Also, scout for weeds, particularly if there is substantial oat and/or soybean residue as this could delay weed emergence and ultimately affect the timing of postemergence herbicide applications.
Resources

University of Minnesota Extension Cover Crops Website

Cover Crop Selector Tool

Cover Crop Seeding Guide (Minnesota Agronomy Technical Note 33)—available from the USDA–Natural Resources Conservation Service)

Post Corn, Going to Soybean: Use Cereal Rye (Minnesota Cover Crop Recipe series, MCCC-114)—available from the Midwest Cover Crops Council

Managing Risk When Using Herbicides and Cover Crops in Corn and Soybean (University of Minnesota Extension)

USDA–Risk Management Agency Cover Crops 

Authors

Lizabeth Stahl, University of Minnesota Extension; Anna Cates, University of Minnesota Extension; Axel Garcia y Garcia, University of Minnesota Extension; and M. Scott Wells, University of Minnesota Extension (Note: This publication was adapted with consent from MCCC under a joint project to produce customized introductory guidance about cover crops for all member states/provinces.)

Reviewers and Contributors

Marisol Berti, North Dakota State University; Frank Forcella, USDA-ARS; Eileen Kladivko, Purdue University; Anna Morrow, Midwest Cover Crops Council; and Bruce Potter, University of Minnesota Extension

The Midwest Cover Crops Council (www.https://www.midwestcovercrops.org) aims to facilitate widespread adoption of cover crops throughout the Midwest by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.
Funding for this project was provided by McKnight Foundation.

October 2019

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. ©2019 by MCCC. All rights reserved.

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