The document discusses the management and benefits of using cover crops in corn/soybean rotations, emphasizing their role in improving soil health and crop yields. It includes practical information on costs, planting techniques, and herbicide considerations, while also presenting survey results regarding cover crop adoption among Illinois farmers. Key questions and concerns from farmers about cover crop practices are addressed, indicating the increasing importance and complexity of implementing cover crops effectively.

1. Joel Gruver
WIU Agriculture
J-gruver@wiu.edu
Using Cover Crops
in a Corn/Soybean Rotation

2. 1922
Cover crops are not new
but we are managing
them in new ways

4. Sciota, IL
40’ wide x 10 mph  > 40 acres per hour

5. Radish on 30” rows
with twin rows of ARG
in the inter-row
Ever seen anything like this?

6. Champaign Cty, IL
Rothermel Farm

8. 1 week

9. Current hot topic
of discussion

11. Talk to your crop insurance agent about CCs

12. Talk to a CCA
about CCs

14. Well… what do you
want your cover
crop to do for you?

15. What needs to be adjusted
to find the best fit?
Where are the best places for
cover crops on your farm?
When is the best time for
establishment and termination?

16. 2012 – SARE Survey
Results

17. Are IL farmers taking
erosion control less
seriously?
Results of IL Conservation Transect

18. Which are most important to you?

19. ? ?
Increase
management
Host
pests
Become a
weed
Prevent
soil drying
Dry out soil
excessively
Interfere w/
equipment
performance
Suppress crop
growth
Tie up N
Add cost
Cover
Crops
Adapted from Magdoff and Weil (2004)
Not all CC effects are positive

22. +30

27. http://www.greencoverseed.com/

28. Cover crops require and reward management
more than broadly adapted technologies
Wow...cover crops
are not idiot-proof!

30. IA Soybean Association’s On-Farm Network®
Replicated Strip Trial Database

32. Carlson, S. 2013. Winter rye cover crop effect on grain crop
yields: Year 4. Practical Farmers of Iowa. Ames, Iowa.

33. Miguez, F.E. and G.A. Bollero. 2005. Review of corn yield
response under winter cover cropping systems using meta-
analytic methods. Crop Science. 45:2318-2329.

34. #1 way to make
cover crops pay!!!

35. EQIP CSP

36. Field operation IA* IL IN* MO*
Fertilizer buggy 4.15 (1.50-
7.50)
4.72 (3.07-6.37) 4.97 (3-15) fert
6.02 (3.50-15)
fert+seed
Harrowing 8.10 (4-
12.50)
6.78 (3-12)
Cultipacking 6.55 (3-10) 8.50 (5-15)
Broadcast w/ ATV 10.35 (8-12) 7.44 (3-12.50)
Conv. grain drill 13 (7.50-20) 11.40 15.89 (13.63-
18.15) s
13 (8-24) sg
14.09 (10-24) gc
No-Till grain drill 15.35 (12-25) 14.60 14.47 (10.80-
18.14)
14.80 (10-24) s
14.25 (5-25) sg
Air seeder 16.40
Per acre costs of cover crop planting operations
based on custom rate surveys

37. Costs Program 1 Program 2 Program 3 Program 4
Seed 11.25 7.50 11.25 9.00
Seeding operation 4.15 15.00 10.00 10.00
Seed incorporation 6.50
Herbicide 2.00 2.00
Termination
operation
6.50 6.50
Total 30.40 31.00 21.25 19.00
Examples of total cover crop management programs ($/ac)
Program 1
Seed: 90 lbs/ac cereal rye
Seeding operation: spread w/fertilizer buggy
Seed incorporation: rolling stalk chopper
Herbicide: 24 oz. glyphosate
Termination operation: 90’ boom spray rig
Program 3
Seed: 90 lbs of cereal rye
Seed bed preparation: none
Seeding operation: aerial seeding
Herbicide: no added cost, burn-down standard
Termination operation: no added cost, burn-down standard
Program 2
Seed: 60 lbs/ac cereal rye
Seed bed preparation: none
Seeding operation: no-till drill
Herbicide: 24 oz. glyphosate
Termination operation: 90’ boom spray rig
Program 4
Seed: 3 bushels of bin-run oats
Seed bed preparation: none
Seeding operation: aerial seeding
Herbicide: none – winter-kill
Termination operation: none – winter-kill
Strong demand has
increased the price
of CC seed

38. IA and IL Aerial Applicator Survey (May-June 2010)
Name Location Experience w/CC Cost
Cady Aerial Spray Rock Falls, IL
no exp., no customer
interest $8.00/a norm app $8.50/a cc
Benoit Aerial
Spraying Kankakee, IL turnips and rye $8.00/a norm app $10.00/a cc
Franks Flying
Service Morrison, IL ryegrass and c. rye $8.00/a norm app $10.00/a cc
Reeds Fly-on
Farming Mattoon, IL
yes, c. rye, small part
of business $8.00/a norm app $12.00/a cc
Killiam Flying
Service Carlinville, IL
rye, wheat on beans,
rye on corn
$8.00/a norm app $10.00/ac
or 10/lb
Curless Flying
Service Astoria, IL ryegrass and turnips $8-15.00/a all app.
Klein Flying
Service
St. Francisville,
IL annual rye and turnips
~$12.50/a cc, $9.00/a liquid
app
Agriflite Services Wakarusa, IN rye, wheat, ryegrass ave $15.00/a for cc app.
Al's Aerial
Spraying Ovid, MI rye and wheat
$10-15.00/a cc $10.00/a
liquid

39. IL CC Business Directory

40. Where will
you be on
2/18?

41. Opportunities for planting cover crops
• Dormant seeding early or late winter
• Frost seeding
• In the spring
• When planting summer crops
• Prevent plant scenarios
• Before canopy closure
• After small grains
• After vegetables
• After seed corn or silage corn
• Aerial or high clearance seeding into standing crops in late
summer/early fall as canopy opens
• After early corn/bean grain harvest
• After full season corn/bean grain harvest

42. Interseeders

43. PSU
interseeder
crimson
clover and
annual
ryegrass are
very shade
tolerant

44. West Union, IA

46. “I run a delayed burn down..... Usually mid to late May.
I have switched back to older chems..... I miss the Callisto, we’re supposed to
only get a few weeks residual, but 2yrs ago I seeded some clover every week til
August..... In August, still fried clover after emergence. With that said, I did
have a bunch of clover pop the next spring, just doubt I got much benefit from
it..... Since it showed up about the week I sprayed.” L. Steinlage, West Union, IA

48. In 2014, we interseeded different mixes of cover crops into both corn and soybeans
with a Hagie high-clearance sprayer equipped with a Gandy dry box with boom hosing
on August 26.

49. 10 most shade tolerant species out of 45 ground covers

50. Species Shade rating
Crownvetch 83
Kura clover 56
Strawberry clover 47
Crimson clover 39
Arrowleaf clover 39
Berseem clover 38
White clover 38
Sub. clover 31
Red clover 30
Birdsfoot trefoil 25
Alsike clover 22
Alfalfa 20
Species Shade rating
River oats 83
Cluster fescue 76
Reed canary grass 69
Orchard grass 66
Smooth brome grass 66
Kentucky bluegrass 60
Tall fescue 49
Annual ryegrass 47
Perennial ryegrass 44
Redtop 41
Timothy 36
Cool season legumes Cool season grasses
Some of these species
may be the future of early interseeding!

52. Soybean herbicides like fomesafen, chlorimuron (in products such as Classic)
and imazethapyr (Pursuit) create significant risk for legumes and brassicas but
are generally not an issue for small grains.
Corn herbicides like atrazine and simazine should be used at less than 1 pound
per acre when cereal grains are used for covers, and less than 0.75 pounds per
acre for most legume cover crops, mustards and annual ryegrass.

54. 1) Persistence of herbicide activity in soil
2) Cover crop sensitivity to herbicide
Herbicides with short half-lives (time it takes for 50% of the active
ingredient to dissipate) are less of a concern.
Factors influencing the rate of dissipation include rainfall, soil texture
and soil pH, etc.
In general, products with a 4 month or less rotation restriction for the
species of interest, close relative, or sensitive species should pose
little problem.
2 main factors impact potential
for herbicide injury to cover crops

55. Partial list of corn herbicides

56. Partial list of soybean herbicides

59. (Corzatt & Bernards, 2014)

60. Corvus Atrazine
Flexstar
Lexar Halex
WIU student
project in 2012
Perform a bioassay
if you have concerns

61. Have you
looked at
this
document?

63. IN FIELD
EDGE OF FIELD
Cover crops
reduce nutrient
losses

64. …while also
improving soil
health

65. Do you scout your fields in the rain?
If not, you are missing a great
opportunity to see soil health in action!

66. Wow! That was cool!
RAINFALL
SIMULATION

69. Low risk cover crop system for a CORN-SOY rotation:
1. No-till drill cereal rye into corn stalks. You can drill (or
broadcast/harrow) in Nov. and still establish a good stand.
2. No-till soybeans into terminated cereal rye. Plant an
earlier group soybean and harvest in September.
3. No-till drill a low C:N cover crop mix (e.g., oats and
radish) that will reliably winter kill.
4. No-till or strip-till corn into the CC residues.

70. Do you know any experienced
Ccers who can answer your Qs?

71. Each Q is answered by multiple IL CC specialists

72. Q. Which cover crops collect/remove nitrogen (N) the quickest or most efficiently?
Q: How do I determine which cover crops are best suited for my soils and typography?
Q. What is the carbon-nitrogen penalty, meaning how many units of carbon to how
many units of nitrogen? How do I account for that?
Q. I am just starting to grow cover crops. Which ones are easier to start with? Which
ones should I stay away from?
Q. Can I plant cover crops on fields in continuous corn?
Q: Which cover crops are better for weed control?
Q. We’ve had trouble getting a good stand of cover crops the last two years. Last year,
we planted cereal rye and radishes on the corn ground going into soybeans. We
planted cereal rye, radish and crimson clover with a plane on ground going into corn.
Our fields are in northeast St. Clair County.
Q. A Monmouth farmer asks, “Is there a better product and/or faster working product
than what I’m doing if the rye has any size to it? Burndown of annual rye is frustrating
and slow. I was told to always use Roundup 32-44 oz., 1 pt. 24-D, A.M.S. on the first
trip. Then the second trip put down my residual. Sometimes with the wet and busy
spring, it is tough to fit in. I want to keep a cover crop on in the winter.”
Q: When cover crops decompose, what amounts of nitrogen do they contribute back
into the soil?
Q: What should I consider about reliability of cover crop seed sources? What about
seed mixes?
Cover crop FAQ on FARMWEEKNOW.COM