This presentation was shared on 1/6 at the IL Specialty Crops, Agritourism and Organic Conference

1. Finding the best fit
cover crops on your
organic farm
Dr. Joel Gruver
WIU – Agriculture
j-gruver@wiu.edu

2. Historically crop rotations
revolved around LEGUMES

3. A typical view 50 years ago

4. Typical rural landscape
in IA and IL today
>90% of landsurface
in corn or soybeans

5. Typical amounts of nitrogen
fixed by legumes (lbs/ac/yr)
Alfalfa 150-300+
Soybeans 150-250
Red clover 75-200
Hairy vetch 75-200
Other annual forage
50-150
legumes

6. Soybean seeds
normally contain
25-50% more N
than was fixed
within their
nodules

7. 133 lbs of K/ac 52 lbs of Ca/ac
Hairy Vetch
3,260 lbs of DM/ac
141 lbs of N/ac
18 lbs of P/ac 18 lbs of Mg/ac

8. Finding the best fit for CCs
within a crop rotation
:
http://www.ncl.ac.uk/tcoa/files/breakcrops_orgagr.pdf

9. Conservation Augmentation
3 broad goals of
ecological Activation
management

10. Terminating spring planted oats with a soil finisher
~ 3 weeks before planting corn
GOAL = biological activation

11. Overview of book contents
• Problems and opportunities for over 500 crop
sequences
• Characteristics of more than 60 crops and 70 weeds
• Crop diseases hosted by over 80 weed species
• Modes of transmission for 250 diseases of 24 crops
• Thirteen sample four- and five-year vegetable and
Rotations
grain crop rotations Managing Crop Rotation Chart
should evolve
with key tasks & steps
not revolve
•Sample worksheets and calculations
• Step-by-step procedure for determining crop rotation
plans

12. What to Look For in A Cover Crop
• Fast germination and emergence
• Competitiveness
• Tolerance to adverse climatic & soil
conditions
• Ease of suppression/residue
management
• Fertility/soil quality benefits
• Low-cost

13. Cover crops have many effects!
Feed
livestock
Cover
Crops
Adapted from Magdoff and Weil (2004)

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

15. Matching specific objectives with species
Grazing
brassicas, clovers, small grains, ryegrass, sorghum-sudan
Nutrient Cycling
brassicas, small grains, annual ryegrass
Bio-drilling
brassicas, sugarbeet, sunflower,
sorghum-sudan sweet clover, alfalfa
N-fixation
clovers, vetches, lentil, winter pea, chickling vetch, sun hemp,
cowpea, soybean
Bio-activation/fumigation
brassicas, sorghum-sudan, sun hemp, sesame

16. Key considerations
How will I seed the cover crop?
What will soil temperature and moisture conditions be like?
What weather extremes and field traffic must it tolerate?
Will it winterkill in my area?
Should it winterkill to meet my goals?
What kind of regrowth can I expect?
How will I kill it and plant into it?
Will I have the time to make this work?
What’s my contingency plan—and risks—if the
cover crop doesn’t establish or doesn’t die on schedule?
Do I have the needed equipment and labor?
Start planning now for next fall!

17. Best single source of info on cover crops is FREE!

18. regularly updated blog on
cover crop management

19. There are lots of opportunities following small grains!

20. Have you tried any forage brassicas?
Hunter

21. #1
opportunity
to make
cover crops
pay

22. Hairy vetch can be successfully planted after
wheat harvest. On the two occasions (out of 18
site-years of the WI Cropping System Trial)
when the red clover failed to establish well,
hairy vetch produced an average of 115 lbs N/a
providing an excellent ―back-up plan‖.
July/August plantings of vetch or
other cover crops are riskier than
frost seeding clover.

23. Frost-seeded clover
the most tried and true
cover cropping system
in the Midwest region

24. Sweet
clover
Mustard

25. http://calshort-lamp.cit.cornell.edu/bjorkman/covercrops/spring-mustard.php

26. Klaas and Mary Martens,
organic innovators in
Central NY State, are
reporting excellent results
with frost-seeded
confectionary mustard
ahead of dry beans

27. Be realistic about potential
cover crop challenges

28. Are you equipped to handle a situation like this?

29. 10’ Howard Rotavator tilling ~ 3” deep with C blades

30. Complete kill after 1 pass
and 2 days of sun

31. Typical weather in 2009/2010 :-<

32. Where are the soybeans??
Traditional organic weed management
often comes up short during wet years
A strong stand of cereal rye was incorporated
~ 2 weeks before these soybeans were planted

33. Organic No-till?
Less
weed seed
germination
Rodale roller
…but few
options for
weed
termination
Cultimulcher

34. Early July 2009

35. Early August 2009

36. Early November 2009
Plot yields ranged from 51.6 to 58.6 bu/ac
No significant differences between systems

37. November 2010
Significant foxtail pressure
but almost no broadleaf weeds
Plot yields ranged from 42-52 bu/ac

38. Soybean health experiment – 6 locations across IL
November 2010
Mustard
Rapeseed
Canola
Cereal rye

39. Bio-strip till
September 2008

40. September 2009 Attempt #2

41. Tillage radish on 30” rows with oats on 7.5” rows
November 2009

42. Radish planted on 30‖ rows using milo plates
in mid-August 2010

44. Ontario, Canada

45. November 2010
Radish planted in
volunteer cereal rye

46. Annual ryegrass variety trial
November 2010

47. Annual ryegrass
w/crimson clover

48. Wheat + radish trial
November 2010

49. What is a cover crop cocktail??
Sunflowers + soybeans+ buckwheat

50. July 17 planting

51. July 29 planting

52. Cover crops generally require more management
than manure or purchased nutrient amendments

55. Many of the 2008
profiles were
updated in 2010!