I shared this presentation at the Effective Cover Cropping in the Midwest conference in Decatur IL on 12/8/2011

1. Finding the best fit
cover crops in
organic farming systems
Dr. Joel Gruver
WIU – Agriculture
j-gruver@wiu.edu

2. A typical view 50 years ago

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

4. This is not
going to work
for organic
farming
systems!

5. What do modern organic farming systems look like?

6. Where do cover crops fit in modern organic farming systems?

7. Cover crops are not the missing puzzle piece(s)
in current crop rotations!
http://www.ncl.ac.uk/tcoa/files/breakcrops_orgagr.pdf

8. 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

9. 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
grain crop rotations Managing Crop Rotation Chart
with key tasks & steps
•Sample worksheets and calculations
• Step-by-step procedure for determining crop rotation
plans

10. Excellent information on integrating cover crops with agronomic crops
http://ohioline.osu.edu/sag-fact/pdf/0009.pdf

11. Conservation Augmentation
3 broad goals of
Activation
ecological
& deactivation
management
underpin effective organic
farming systems

12. More “conservation” is needed!
Organic farm in NW Missouri

13. Terminating spring planted oats with a soil finisher
~ 3 weeks before planting corn
biological activation (enhanced nutrient cycling)
& deactivation (weed suppression)

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

15. 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)

16. Avoid haphazard use of cover crops
What am I
supposed to do
now?
Develop a plan to increase beneficial effects
while minimizing negative effects

17. Matching specific objectives with species
Grazing
brassicas, clovers, small grains, a. ryegrass, sorghum-sudan
Nutrient scavenging/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
Weed suppression
brassicas, sorghum-sudan, cereal rye, buckwheat

18. Have you tried any forage brassicas?
#1
Ethiopian opportunity to
cabbage Winfred
make cover
crops pay
http://www.jennifermackenzie.co.uk/2005/12/brassicas.html
Hunter

19. Historically crop rotations
revolved around LEGUMES

20. Do all legumes add N to the soil?
Soybean seeds
often contain
>25% more N than
was fixed within
their nodules

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

22. 133 lbs of K/ac 52 lbs of Ca/ac
Only legumes ―fix‖ nitrogen
Hairy Vetch
3,260 lbs of DM/ac
141 lbs of N/ac
All cover crops capture and recycle plant essential nutrients
18 lbs of P/ac 18 lbs of Mg/ac

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

24. Best collection of information on cover cropping in the Midwest

25. 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

26. Additional 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!

27. Effective multi-tasking or cover crop chaos???

28. Mixes can add
both performance
and challenges!

29. Do you see any cover crops??

30. Frost seeded
red clover
the most tried
and true
cover cropping
system
in the Midwest
region

31. There are lots of opportunities following small grains!

32. 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.

33. Sweet
clover
Mustard is not the only
option for frost
seeding

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

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

36. Mustard variety trial at the WIU Organic Research farm
(Spring 2011)
Pacific Gold IdaGold
slower to mature but matures faster but
more biomass less biomass

37. Mustards (and other brassicas) are very
responsive to N availability

38. Mustards (and other brassicas) are easy to
kill and decompose rapidly

39. Sunflowers perform well planted mid-summer
following spring planted cover crops

40. July 17 planting

41. July 29 planting
Not recommended

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

43. 10’ Howard Rotavator tilling ~ 3” deep with C blades

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

45. Typical weather in 2009/2010 :-<

46. Are you familiar with the fence post principle?
Zone of maximum biological
activity and rapid residue decay
Deeper burial does not optimize decay but sends weed
seeds into deep dormancy and brings deeply dormant
weed seeds to the surface where they germinate slowly

47. 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

48. JD 730 Air-Disk drill on Jack Erisman’s farm in Pana, IL
Jack uses this rig to drill soybeans on 6" rows (~ 280,000/ac)
while also dropping about 2 bushel of rye and some
micronutrients

49. Dramatic impact of timing and weather on weed pressure

50. Planted 1 week later after a heavy rain

51. Lots of weeds but very few
towering monsters of maternity :->

52. 40 lbs/a of cereal rye seeded over
soybean rows at planting
provided some weed
suppression and no yield
loss for 2 reps

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

55. Early July 2009

56. Early August 2009

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

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

59. About 1 month ago

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

61. Does anyone recognize this cover crop?

62. A different approach to organic no-till beans
Soybeans no-till drilled
into pasture after scalping
with a flail mower

63. Bio-strip till
September 2008

64. September 2009 Attempt #2

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

66. Radish planted on 30‖ rows (~ 2.5 lbs/a)
using milo plates in mid-August 2010

67. Close up of wide row radishes in fall 2010

68. Cultivating wide row radishes in fall 2010

69. Ridged radishes in spring 2011

70. Planting popcorn on radish
ridges in spring 2011

71. Field appearance after 1 round

72. Ontario, Canada

73. Recently cultivated radishes in fall 2011

74. Annual ryegrass variety trial
November 2010

75. A. ryegrass roots
grow deep even
on poorly drained
soils

76. A. ryegrass is
hard to kill with
tillage

77. Wheat + radish trial
November 2010
1lb/a of radish - > 2.5 bu yield gain

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

79. Updated in 2010!

80. Successful organic
farming takes a high
level of skill and will!