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Cover Crop Benefitsin
Agriculture Production
Michael Plumer
Cover Cropsmanaging for benefits
• Radish weed control, nematode reduction
• Cereal rye weed control, nematode reduction
• Hairy vetch weed control by mulch• Annual ryegrass nematode reduction, mulch
effect• Crimson clover mulch effect• Rapeseed disease reduction, nematode
reduction• Spring oats fall weed control
Disease Reduction by Cereal rye and rapeseed
3 year study at 8 locations in Illinois
• Septoria brown spot- significant reduction behind cover crop, especially following cereal rye
• Bacterial blight –no infection found behind cover crop
Bond, SIU—Eastburn, U of Il.
Disease Reduction
• Rhizoctonia – significantly reduced with cereal rye and rapeseed
– Increased soybean stand behind cereal rye and rapeseed
– Reduction in Rhizoctonia lesions
– Soybean yield significantly higher following cereal rye vs no cover crop
Bond, SIU—Eastburn, U of Il
Rapeseed in late April controlling winter annuals
Soybean after green manure of rapeseedSoybean – No winter cover cropSDS showing
Disease suppression by crops
Treatment SCN
eggs/100cc
Changes in
Egg count
SDS Foliar
Disease
DX 8/26
Foliar
Disease
AUDPC
Yield
(bu/A)
Fallow (No winter crop) +589 a 25.2 a 157.7 a 65.4 b
Cover crop (rapeseed) -313 b 16.8 b 103.9 a 67.5 ab
Green manure (rapeseed) -691 b 5.5 c 37.1 b 69.6 a
P > F .002 .0001 .001 0.07
Means followed by the same letter are not significant (P=0.05), according to Fisher’s LSD test.
J. Bond, SIU
Soybean cyst nematodes
• Significant reductions following cereal rye and rapeseed at all 8 locations all 3 years
3 year 8 location summary
• Cereal rye and rapeseed showed that they provided increased protection of soybeans against the effects of:
– SDS
– Rhizoctonia
– Soybean cyst nematodes
– Brown stem rot ----cereal rye
Bond, SIU --Eastburn, U of Il.
Soybean
Cyst
nematode
suppression
by annual
ryegrass
Treatment NW Plot yield SW Plot yield
Bare soil 48.9 48.2
Cereal rye 53.8 52.3
Annual ryegrass 55.7 60.6
Plumer, U of Il
Soybean Cyst Nematodes
Egg Count
Bare Cereal Rye Annual Ryegrass
NW 7533 717* 117**
SW 3650 320* 0**
LF 1559 722* 386*
JA 1202 390* 279*
Dense stand of crimson clover controlling winter annuals and early spring weeds
Annual ryegrass winter annual control
Ryegrass suppression of Palmers amaranth
U of Florida
Ryegrass cover crop
Hairy Vetch, mulch controlling most winter annuals
Hairy vetch mulch with only 2,4-D, atrazineWeed control variable due to speed of vetch decomposition
difference in vetch varieties
Understanding what a good stand really is for weed control
Annual ryegrass with vetch and crimson clover 5 days after herbicide application--2,4-D and 1.25# ae glyphosateControls winter annuals
Understanding cereal rye and weed control
• Good allelophathy when young
• Requires uniform stand seeded on time– Same time as wheat for best control
• Seeding rate for weed control 70-90#/a– Depends on planting date
• For good weed control must grow till anthesis– Earlier kill, reduces level of weed control -- only
winter annuals
• There are significant differences in varieties
Weed Control
• Controlling resistant weeds with cereal rye
– Glyphosate resistant marestail (horseweed)
• Herbicide program: $40/a + not always effective
• Cereal rye $16-24/a
– Mulch and allelopathy effect from high residue cereal rye cover crop
Aerial seed with cereal rye, radishHad sunlight on the ground at seeding
Serious mares tail population, 3 year study
Cereal rye70#/a
WEED CONTROL
Plumer2012
Replicated trial, rye residue removed mid May 2013
% Resistant Marestail Controlwith cereal rye cover crop
0
20
40
60
80
100
120
14 day rating 30 day rating
no rye-- 2 glyphosateapplications
rye removed
rye cover
3 year study; 8 replications
Glyphosate sprayed mid May and 2 weeks later at 1.5#/a ae
Uniform solid stand is critical for weed control
Rye at pollination, only time to get good controlby crimping– ave. 95+%
Crimped and drilled soybeans
This is the level of rye cover that is neededfor good weed control
Stage of
growth when
cereal rye can
damage corn
the most
Allelopathy issues
Corn must be planted 2” deep and slot tightly closedto reduce problem, or wait 2 weeks after killing rye to plant
Mature cereal rye mulch with only glyphosate
burndown- June planting
Corn into high residue issues
• Cover crop removes all the nitrogen in top 12” of soil- soil tests show < 3#/a at cover termination
• Requires in furrow nitrogen, and/or 50-70#/a surface applied at planting- issue of tie up surface applied as well—or 30+ #/a starter
• Early research shows cover crop nitrogen takes temperature, moisture and time to become available
Oats and radish controlling winter annuals
New radish developments
• 2014 there were 34 different varieties
• Many have totally different qualities
– Kill different nematodes or propagates nematodes
– Michigan State University doing extensive work
• Work starting on evaluation for soybean cyst nematode, root knot nematode, sugar beet nematode, corn nematodes
Radish- which one do you want
Consider cover crop strip till
• Requires precision planting
• Requires good GPS autosteer/RTK
• Needs to be timely– Getting it planted on time is important
• Reduce seeding rate in strip– Radishes 1—1.5#/a
– Rapeseed 3-4#/a
• Controls winter and early weeds while providing “bare, tilled” row for early planting
How to plant one cover crop in 30” rows
Bio-strip till with radish and rapeseed
Bio strip till 30” cover crops
1.5#/a radish Rapeseed 2#/a
Feb. 15
Planting on bio-till row of dead Radish
Seeding on the Radish winter killed row—notice low residue in row
Establishment –early or perennial cover crops
• Annual ryegrass/legumes establishment at V-6 to7
• Seeding middles onlyimproves establishment andplanting crop next spring in strips
• Use less seed• Increased fall growth• Better winter hardiness• Increased fall grazing• Improve weed control
Dr. W Curran, Penn State U.
Weeds
If Tillage and Herbicides controlled weeds---
Why are we still doing it every year??
Dr. D. Beck
Questions??