i shared this presentation at the MN Organic Conference on 1/12/2013

1. Cover crops
for organic field cropping systems in MN
Joel Gruver
WIU- Agriculture
J-gruver@wiu.edu
(309) 298 1215
http://www.slideshare.net/jbgruver/

2. Almost
500 miles!
Macomb

3. Macomb IL Apr 21 Oct 11 180

4. 15.4% ↑
http://www.weather.com/outdoors/agriculture/growing-degree-days/

5. Historically,
10.6% ↑
than Saint Cloud
29% more GDD @ 40F
http://www.weather.com/outdoors/agriculture/growing-degree-days/

6. Very few opportunities for CC before or after corn and soybeans
http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Annual_Statistical_Bulletin/2011/Whole%20Book.pdf

7. Many more opportunities for CC after
wheat, barley, oats, rye, peas…
http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Annual_Statistical_Bulletin/2011/Whole%20Book.pdf

8. small grains + warm season grasses + a. ryegrass + buckwheat + flax
mustard + radish + rapeseed/canola + turnip
alfalfa + clovers + vetch + peas + soybeans
6 mixtures of c. rye, a. ryegrass, c. clover, oats, radish, peas + vetch

9. Crop
planted
on 5/15
and
harvested
on 10/1

10. Crop
planted
on 4/15
and
harvested
on 8/15

11. MCCC website also provides links to
lots of good extension publications

14. Lots of potential cover crop species are described in this publication

18. Wisconsin data suggest that approximately 70% of
whole-plant N will become available in the first year
following clover, most released before corn begins its
period of rapid uptake.

19. Usually, the best conditions for frost seeding occur in mid to late
March. Low overnight temperatures cause the surface to freeze
and crack. Warm daytime temperatures thaw the surface, sealing
the cracks. If daytime thawing occurs, the daily “window” for
seeding lasts only a few hours, beginning at dawn. With
subfreezing daytime temperatures, seeding can occur anytime
during the day. Seed can be broadcast until mid-April if cracks are
present and the traditional frost-seeding window is missed.

20. Gary Sommers’ farm in Clinton, Wisconsin, is just down the road from his boyhood
home. He grows corn, soybeans, and winter wheat on 1,475 of his 1,500 acres. The
remaining 25 acres are enrolled in the Conservation Reserve Program.
Gary mainly uses cover crops on his steeper fields. Usually he sows cover crops—
including buckwheat, soybeans, oats, and Berseem clover—after harvesting winter
wheat in mid-July. The following spring he plants these fields to corn. Cover crops
which do not winter-kill are terminated in the fall to prevent corn planting delays.

22. Match CC objectives with species
Grazing
GRAZING = #1 way to make cover crops pay!
brassicas, clovers, alfalfa, small grains, annual ryegrass, sorghum-sudan
Nutrient scavenging/cycling
brassicas, small grains, annual ryegrass
Bio-drilling
brassicas, annual ryegrass, 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

23. Forage kale Oats, turnips, annual ryegrass and wheat
Oats, turnips and cereal rye Mystery brassica

24. On farms with livestock, many
failures can be turned into success!

25. Franzluebbers AJ and JA Stuedemann. 2008.
Soil physical responses to cattle grazing cover
crops under conventional and no tillage in the
Southern Piedmont USA.
Soil and Tillage Research 100, 141-153.
Cover crops (winter or summer) can provide high-
quality forage and increase economic return and farm
diversity, but some farmers have been reluctant to take
this advantage due to perceived “compaction” caused
by animal trampling.
Grazing of cover crops can compact soil, but not to the
detrimental levels often perceived.

27. Crop Rotation on Organic Farms:
A Planning Manual provides an
in-depth review of the applications
of crop rotation-including
improving soil quality and health,
and managing pests, diseases, and
weeds. Consulting with expert
organic farmers, the authors share
rotation strategies that can be
applied under various field
conditions and with a wide range
of crops.
Crop Rotation on Organic Farms
is most applicable to farms in the
Northeastern United States and
Eastern Canada but is worth a look

28. Start planning today!
• Anticipate planting windows
• Match objectives with species
• Confirm seed availability
• Make sure seeding equipment is ready
• Identify realistic termination methods
• Allocate labor
• Develop contingency plans

29. When can you plant CCs?
• Dormant seeding early or late winter
• Frost seeding
• In the spring
• In the spring w/ cash crop
• Prevent plant scenarios
• At last cultivation
• After small grains
• After vegetables
• After seed corn or silage corn
• Aerial or high clearance seeding into standing
crops in late summer/early fall
• After long season crops

30. What is this CC?
Phacelia

31. WIU Organic research farm – May 2012

32. Very dense
rooting at the
soil surface

34. Mustard variety trial at the Allison farm in early June 2011
Pacific Gold Ida Gold
Slower to mature Faster to mature
More biomass Less biomass

35. 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 ~2 bushel of rye and
some micronutrients

36. Zumbrun Farm
Northern Indiana

38. Drilling cover crops after small grain harvest

39. There are many options other than drilling

40. Magness Farm in Maryland

42. Slurry seeding

44. What is PRECISION COVER CROPPING??
1) Planting of cover crops with a precision planter
2) strategic placement of cover crop rows in relation
to other cover cover rows and/or the following cash
crop rows (often using GPS guidance)
3) Strategic placement of cover crops in specific
fields or parts of fields
4) Selection and management of cover crops to
achieve specific objectives

45. Precision planting

46. http://www.extension.org/pages/64400/radishes-a-new-cover-crop-for-organic-farming-systems

47. Insecticide boxes can be used for metering small seeds

48. Joe Rothermel’s new rig

49. Cover crops planted with insecticide
boxes while stripping

50. September 2008

52. Attempt #3
Radish planted on 30” rows using
small milo plates in mid-August 2010

53. Corn following cover crop experiment (2011)
Relative
Cover crop system
corn yield
Volunteer oats 79%
Radishes planted on 30” 99%
Radishes drilled on 7.5” 91%
Corn planted directly over radish rows

54. May 2012

55. Radish planted on 30” rows with RTK guidance on August 29th
right before Hurricane Isaac rolled in

56. 4 days later

58. 7 days after planting

59. 10 days after planting

60. ~ 1 month later

62. Why are the inter-rows so clean?

63. We had just cultivated the radishes!

64. ~ 2 weeks later

66. December 2012
We are planning to “freshen” the radish rows
with a Yetter strip till bar before planting corn
directly over the radish rows

67. Precision radishes w/o peas
Precision planted radishes w/ peas from 5 ft of row

68. What is the optimal
seeding rate for precision
planted radishes?
4-6 seeds per foot is probably often the
best ROI but ~16 seeds per foot produced
the most biomass for us this fall
higher is probably better
the later you plant

69. Radishes in fall 2011
~ 20 more bushels/a where
we cultivated in the fall

71. Ridges with
dead radish residues
in spring 2011

72. Planting popcorn
on radish ridges
in May 2011

73. Planted beautifully
but we decided to
replant after a
month of relentless
rain :-<

74. Fall 2011

75. Fall 2012

76. Crimson Chick
clover peas
Green Fava
lentils beans

77. Sunflower Oats
Rapeseed Phacelia

78. We are trying to identify the best
combinations of winter hardy
and winter-kill CCs for row and
inter-row positions

80. A little extra N can make a big difference
+20 lbs N/a
Radish biomass = 2X

81. Same planter pass
5 buffer rows were not Preceded by spring
preceded by a CC planted radish
Most years the extra transpiration
would probably have been helpful
on this wet farm

82. Last summer, we undercut our small grain stubble using
a no-till cultivator and a tractor with RTK guidance

85. Cover crop cocktail
Fallow strip no-till drilled after
undercutting

86. Triple S mix
Sunflowers, Soybeans & Sunnhemp

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

89. http://greencoverseed.com/

90. Planting into poorly digested red clover residues
25-50% stand loss
Near perfect stands in all other corn
plots on the farm this past spring

91. Annual ryegrass after chisel plowing
Chisel plowing made the
next pass with a rotavator
easier and more effective

92. No-till drilling soybeans into standing rye
Early June 2011

93. 15’ wide roller built by a local farmer

94. Mid-June 2011
Rolled after drilling

95. Early July 2011

96. Our conventional-till beans are
looking good, right?

97. August 2011

98. November 2011
The NT bean plots yielded
~10 bu more than the best
tillage system plots

99. April 2012
In our experience, a strong stand of rye is critical

100. Planting into 5-6’ tall rye on May 11

101. Double drilled with 4” offset

102. June 2012

103. All of July :-<

104. Our 2012 NT bean yields ranged from
~ 30 to ~ 60 bu/a
Wet hole yielded
very well
Better drained areas of
the field yielded poorly

105. CCs affect many agronomic factors
simultaneously
Control
erosion
Feed
livestock
Cover
Crops
Adapted from Magdoff and Weil (2004)

106. Not all effects 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 drying
Add cost
Increase
management
Adapted from Magdoff and Weil (2004)

107. Greater precision in your cover
cropping practices will increase the
likelihood of intended outcomes
More positive and fewer negative effects

108. I wish you all success in 2013!