March 2025
Authors Jason Cavadini and Eileen Kladivko
Midwest Cover Crops Council (MCCC-136)
University of Nebraska Extension (G2351)
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 publication provides an introductory approach to integrating cover crops following corn silage and before corn or soybeans. These cover crops can have many benefits, such as erosion control, weed suppression, improved soil health, and quality forage production.
Planning and Preparation
- Planning—Start planning early. Educate yourself by talking to experienced cover crop users, attending conferences and field days, and reading as much as possible about cover crops. Start small and determine your purpose and objectives for using cover crops. If needed, arrange for equipment, additional labor, or custom operators.
- Corn hybrid and planting—Plant the corn silage crop early and use a hybrid within the adapted maturity range for your location. This will allow you to plant your cover crop earlier and increase fall growth.
- Residual corn herbicides—Consult your agricultural supplier regarding residual corn herbicides that could cause concerns for newly planted cover crops. Cereal grains (rye, oats, and wheat) are not affected by most pre-emergence residual herbicides but are somewhat affected by post-emergence herbicides. If using rapeseed in your mix, it may be sensitive to carryover from herbicides. If cover crops will be grazed, additional herbicide restrictions may apply.
- Seed purchase—Order your seed early from a reputable seed supplier to ensure a good germination rate, purity of seed, and that all seed has a seed analysis tag. Specific varieties of cereal rye, wheat, or oats may produce significantly more growth, but they are also more expensive than variety not stated (VNS) seed.
Fall Work
- Corn silage harvest—Harvest fields where a cover crop is to be planted first, if possible.
- Tillage or no-tillage—No-till drilling into corn silage stubble is usually the best strategy to use unless tillage is necessary to incorporate manure, fertilizer, or lime, or needed to smooth out the seedbed, such as deep wheel tracks after corn silage harvest. The tillage should be completed as soon as possible and before seeding the cover crop.
- Timing of planting—Ideally, plant your cover crop as soon as possible after silage harvest. Plant the oats cover crop mix or oats alone by Sept. 7. Oats will not grow enough to justify their use after this date. For winter wheat only, plant before 50% frost date. For rye only, plant before two weeks after the 50% frost date. In northern Nebraska, this would be before Oct.15; in southern Nebraska, before Nov. 1. Use the Cover Crop Selector Tool (in the Resources section) for more precise dates for your county. These dates are guidelines; the sooner these cover crops are planted in the fall, the better.
- Seeding rate for a mix—Drilled: oats, 20 lbs./acre; wheat, triticale, or rye, 25 lbs./acre; rapeseed, 1 lb./acre. Broadcast: oats, 25 lbs./acre; wheat, triticale, or rye, 30 lbs./acre; rapeseed, 2 lbs./acre.
- Seeding rate for oats alone—Drilled: 30–40 lbs./acre; if grazed, 40–55 lbs./acre.
- Seeding rate for wheat or rye alone—25–35 lbs./acre; if grazed, 45–60 lbs./acre. Shallow incorporation: oats, 45–60 lbs./acre; wheat, 50–65 lbs./acre; rye, 50–65 lbs./acre.
- Planting method—If you include the brassica rapeseed, seeding depth is limited as these are small seeds. A depth of 0.50 inch is best. If you have a drill with two boxes, you can dribble the rapeseed on top of the ground and then drill your cereal grain to a depth of 0.75–1.50 inches.
Spring Work
- Termination timing—Oats and rapeseed will usually winter-kill. Terminate the wheat, triticale, or cereal rye in the spring when plants are 6–12 inches tall and actively growing or about two weeks before planting corn or soybeans—whichever comes first. Many experienced growers will terminate wheat, triticale, or cereal rye the same day as planting corn or soybean, or within one week, particularly in irrigated situations. This provides an extra benefit for weed control. Risk of wheat stem maggot damage to corn seedlings increases when corn is planted into a green, non-terminated, winter cereal grain cover crop. Another concern is that cover crop residue with a high carbon-to-N (C:N) ratio can reduce soil-available N. Starter N fertilizer is recommended at planting or sidedress as soon as possible to offset this early immobilization when the corn has a high N demand. New cover crop users should terminate earlier when the cereal crops are smaller for corn. Planting green into soybeans is much less risky and could be implemented by new cover crop users.
- Termination herbicide—Wheat, triticale, and cereal rye can typically be terminated with a full rate of glyphosate (1 lb. acid equivalent/acre) after these crops begin growing in the spring. Effectiveness and rapidity of termination improve if winter cereal grain grows rapidly and air temperatures are warmer.
- Termination modifications for dry weather—Watch the weather and be ready to modify your termination plans. In a dry spring, cereal grain crops have the potential to use moisture that the cash crop will need, so terminate cover crops sooner to allow rainfall to make up the deficit.
- Termination modifications for wet weather—In a wet spring, be ready to take advantage of any break in the weather and/or use low axle weight sprayers.
- Option to harvest cereal rye, wheat, or triticale as a silage crop—A cereal grain cover crop planted in the fall and harvested at boot stage can provide a substantial amount of good quality forage. Waiting for the cereal grain cover crop to reach the boot stage (mid-May to early June) will delay planting of the next corn or soybean crop. If this crop is to be insured, then the small-grain cover crop should be terminated and corn or soybeans planted before the crop insurance late-planting deadline.
- Corn or soybean planting—Almost all modern planters and drills are fully capable of planting corn or soybeans into a clean, small-grain cover crop. Planter adjustments are usually needed to ensure correct planting depth and seed furrow closure.
- Scouting after planting—Scout for corn or soybean emergence, population, and insect pests (e.g., wheat stem maggot in corn). Scout for weeds because substantial small-grain residue, especially cereal rye, can delay emergence of annual weeds, which may then delay the need for and timing of applying post-emergence herbicides.
Resources
Cover Crop Selector Tool —available from the Midwest Cover Crops Council, https://www.midwestcovercrops.org
Post Corn, Going to Soybean: Use Cereal Rye (Nebraska Cover Crop Recipe series, MCCC-107)
Post Corn Silage, Going to Corn: Use Cereal Rye (Iowa Cover Crop Recipe series, MCCC-121)
Post Corn Silage, Going to Soybean: Use Cereal Rye (Iowa Cover Crop Recipe series, MCCC-122)
Managing Residual Herbicides with Cover Crops (Institute of Agriculture and Natural Resources, Univ. of Nebraska)
How Herbicide Labels Restrict Using Cover Crops as Forage (Institute of Agriculture and Natural Resources, Univ. of Nebraska)
Corn and Soybean Herbicide Options for Planting Cover Crops for Forage in Fall (Institute of Agriculture and Natural Resources, Univ. of Nebraska)
Residual Herbicides and Fall Cover Crop Establishment (Purdue Extension Weed Science publication)
Terminating Cover Crops: Successful Cover Crop Termination with Herbicides (Purdue Extension publication WS-50-W)
Authors
Gary Lesoing and Katja Koehler-Cole, University of Nebraska-Lincoln (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
Caro Córdova, Nathan Mueller, and Jennifer Rees, University of Nebraska-Lincoln; Eileen Kladivko, Purdue University; Anna Morrow, Midwest Cover Crops Council
The Midwest Cover Crops Council (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.
December 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. ©2022 by MCCC. All rights reserved.
Midwest Cover Crops Council (MCCC-135)
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
The following recipe provides an introductory approach to integrating a cover crop into a wheat-based rotation with soybean or corn. Planting a cover crop blend that predominantly consists of cool-season species and is winter-killed adds diversity and provides soil armor through summer and spring. However, in some situations added ground cover in the spring in combination with excess soil moisture could be a problem unless winter cereals (winter rye, wheat, or triticale) are included in the mix.
Planning and Preparation
- Planning—Consult with university Extension staff, local NRCS staff, and experienced producers to gain insight on the practice. Start small while exploring new practices. In South Dakota, timeliness is important due to the shorter growing window. Always focus on your objectives, such as whether you are growing the cover crop for ground cover, fall grazing, nutrient cycling, etc.
- Small-grain variety and planting—Small-grain varieties such as wheat or oats do not need to be changed or modified to incorporate cover crops following grain harvest or haying. Planting small grains early in the spring is important for good growth and development, which also typically results in earlier harvest and allows more time for cover crops to grow before a frost.
- Residual herbicides—A blend consisting primarily of cool-season cover crops such as cereal grains (oat, barley), brassicas (radish, turnip, rapeseed), and legumes (field pea), and some warm-season grasses such as millet and sorghum-sudangrass have shown good tolerance to commonly used herbicides. If the cover crop is intended for grazing in the fall/winter, it is critical to follow grazing restrictions stated on the herbicide label.
- Seed source—Planning ahead and ordering seed early with the objective in mind is important. Most cover crop seed dealers have their own pre-mixed blends but are willing to custom-mix upon request. Follow the seed label and review the individual species to make sure that the growth habit of each is ideal for the planting time. If opting for a mix of only one or two species, labeled varieties usually perform better than variety not stated (VNS) seeds.
Summer/Fall Work
- Harvest—Harvest wheat/oats at the normal time. If weed pressure is high, you can spray glyphosate or other herbicides with the least residual effects. Herbicides are a better option than tillage as stirring the soil can dry it out and reduce germination. Baling small-grain residue is common in South Dakota but can make establishment of the cover crop difficult where the windrows were present.
- Timing of planting—In South Dakota, wheat and/or oats are generally harvested from the second week of July to the first week of August. Planting cover crops immediately following harvest is recommended so that the seasonal window can be maximized. A mix consisting mostly of cool-season annual species grows well as temperatures start to gradually decrease. Use the Cover Crop Selector Tool (in Resources section) for precise seeding dates.
- Planting method—Determining seeding depth is tricky when planting a mix with various seed sizes. Drilling to a moderate depth of 0.50–0.75 inch will be good for most mixes. Tilling or soil disturbance is not recommended as this may cause unwanted weed growth.
- Cover crop types—Diversity of species in a mix is good and typically will provide the best benefits. The general rule of thumb is to select cover crops that are of contrasting growth habit to the subsequent cash crop. For example, if the next season’s cash crop is corn, planting cover crop blends that have a higher proportion of cool-season broadleaves is suggested; if the next season’s crop is soybean, then a mix with more cool-season grasses would be ideal. If wheat or other small grains are to be raised for seed purposes, cover crop blends that contain winter cereals (e.g., winter wheat, winter rye, winter triticale) are not suggested.
- Seeding rate—Seed size and proportion in the mix determines the seeding rates. For example, a mix high in large-seed species such as peas and oats can be higher than the ones dominant in brassicas. Typically, the seeding rate of commonly marketed cover crop mixes can range from 15 to 30 lbs./acre. The full seeding rate of individual species can be found in Cover Crop: Common Species and Properties of South Dakota (see Resources).
- Tillage—Tillage or soil disturbance is not suggested.
- Fertility—Fertilizer is not usually required for a cover crop mix with well-balanced species. However, producers who have livestock and intend to maximize growth for fall/winter grazing have shown interest in using low rates of fertilizer. Although there are no specific guidelines on fertilizer rates for various cover crop blends, using nitrogen rates in the range of 30–40 lbs. N/acre can enhance cover crop growth and establishment, especially following high-yielding wheat crops.
- Grazing—Producers who prefer to grow cover crops after small grains for grazing in the fall/winter can slightly increase the proportion of cool-season grass species such as oats and barley. Include at least 60% grasses in the mix for grazing. To assist in calculating the amount of grazing your cover crop can offer, refer to the Grazing Cover Crop Calculation App (in Resources).
Spring Work
- Starter fertilizer—No modifications to your typical fertilization program are required for planting soybean or corn. However, there are a few considerations for planting corn. After a cover crop has winter-killed, get a current soil test to look at nitrates and sulfur. Cover crops can sequester nitrogen, which is a desired attribute to reduce leaching or runoff. But mixes with a high proportion of Brassica species (radish, turnip, rapeseed) can use quite a bit of sulfur. Soil-testing and applying these nutrients as needed to minimize the chance of nutrient deficiency is a good practice.
- Termination—Typical cover crop blends should winter-kill in South Dakota. However, mild winters can leave a few plants the next spring. Timely scouting and herbicide application as needed is suggested for uniform control of cover crop plants that survived the winter. Some mixes with winter annuals such as winter triticale, cereal rye, or winter camelina will require spring termination.
- Soybean or corn planting—It is usually best to no-till plant cash crops into the dead/dry or standing cover crop. Almost all modern planters and drills are fully capable of planting soybean or corn into terminated cover crop residue. Check planting depth and seed furrow closure shortly after beginning.
- Scouting—After planting soybean or corn, scout for crop emergence and population. Additionally, scout for weeds since cover crop residue can often delay emergence of annual weeds, which may delay the application of post-emergence herbicides.
Resources
Cover Crop Selector Tool—available from the Midwest Cover Crops Council, www.midwestcovercrops.org
Cover Crop Species Selection for Grazing (USDA-NRCS publication SD-FS-56)
Herbicide Residual Effects on Cover Crops after Wheat (South Dakota State University Extension)
Cover Crop: Common Species and Properties of South Dakota (USDA-NRCS)
Grazing Cover Crop Calculation App (Jotform app)
Author
David Karki, South Dakota State University 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
Eric Barsness, USDA-NRCS; Anthony Bly, South Dakota State University Extension; Eileen Kladivko, Purdue University; Anna Morrow, Midwest Cover Crops Council
The Midwest Cover Crops Council (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.
December 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. ©2022 by MCCC. All rights reserved.
Eric Lee-Mader, Anne Stine, Jarrod Fowler, Jennifer Hopwood and Mace Vaughanby – Xerces Society for Invertebrate Conservation with contributions from the USDA Natural Resources Conservation Service
August 2017
Kim Cassida and Joe Paling – Michigan State University Extension
February 2020
2019 MSU Cover Crop Variety Test Report
Source link here.
2017 MCCC Annual Conference Presentation – Vegetable Crops Track
Dan Brainard, Ben Werling – Michigan State University and Ralph Oomen, Michigan Farmer
March 2017
Mustard family cover crops for crop establishment and pest management in vegetables
Practical Farmers of Iowa
November 2016
Soybean Herbicides: Restrictions When Planting, Grazing or Feeding Cover Crops
Source link here.