This document discusses the benefits of various cover crops for agriculture production. It summarizes research showing that cereal rye and rapeseed provided increased protection for soybeans against soybean cyst nematodes, Rhizoctonia, brown stem rot, and foliar diseases like Septoria brown spot. Cereal rye and annual ryegrass were shown to significantly reduce soybean cyst nematode egg counts. Cover crops like cereal rye, rapeseed, and annual ryegrass also provided effective weed control through mulching and allelopathy. The document provides tips for establishing cover crops and using them in no-till systems for weed control and other benefits.
2. Cover Crops
managing for benefits
โข Radish weed control, nematode
reduction
โข Cereal rye weed control, nematode
reduction
โข Hairy vetch weed control by mulch
โข Annual ryegrass nematode reduction, mulch
effect
โข Crimson clover mulch effect
โข Rapeseed disease reduction, nematode
reduction
โข Spring oats fall weed control
3. Disease Reduction by Cereal rye and
rapeseed
3 year study at 8 locations in Illinois
โข Septoria brown spot- significant reduction
behind cover crop, especially following cereal
rye
โข Bacterial blight โno infection found behind
cover crop
Bond, SIUโEastburn, U of Il.
4. Disease Reduction
โข Rhizoctonia โ significantly reduced with cereal
rye and rapeseed
โ Increased soybean stand behind cereal rye and
rapeseed
โ Reduction in Rhizoctonia lesions
โ Soybean yield significantly higher following cereal
rye vs no cover crop
Bond, SIUโEastburn, U of Il
6. Soybean after green manure of rapeseedSoybean โ No winter cover crop
SDS showing
Disease suppression by crops
7. 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 Fisherโs LSD test.
J. Bond, SIU
8. Soybean cyst nematodes
โข Significant reductions following cereal rye and
rapeseed at all 8 locations all 3 years
9. 3 year 8 location summary
โข Cereal rye and rapeseed showed that they
provided increased protection of soybeans
against the effects of:
โ SDS
โ Rhizoctonia
โ Soybean cyst nematodes
โ Brown stem rot ----cereal rye
Bond, SIU --Eastburn, U of Il.
10. 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*
11. Dense stand of crimson clover controlling
winter annuals and early spring weeds
18. Annual ryegrass with vetch and crimson clover 5 days after
herbicide application--2,4-D and 1.25# ae glyphosate
Controls winter annuals
19. Understanding cereal rye and weed
control
โข Good allelophathy when young
โข Requires uniform stand seeded on time
โ Same time as wheat for best control
โข Seeding rate for weed control 70-90#/a
โ Depends on planting date
โข For good weed control must grow till anthesis
โ Earlier kill, reduces level of weed control -- only
winter annuals
โข There are significant differences in varieties
20. Weed Control
โข Controlling resistant weeds with cereal rye
โ Glyphosate resistant marestail (horseweed)
โข Herbicide program: $40/a + not always effective
โข Cereal rye $16-24/a
โ Mulch and allelopathy effect from high residue
cereal rye cover crop
21. Aerial seed with cereal rye, radish
Had sunlight on the ground at seeding
25. % Resistant Marestail Control
with cereal rye cover crop
0
20
40
60
80
100
120
14 day rating 30 day rating
no rye-- 2 glyphosate
applications
rye removed
rye cover
3 year study; 8 replications
Glyphosate sprayed mid May and 2 weeks later at 1.5#/a ae
29. This is the level of rye cover that is needed
for good weed control
30. Stage of
growth when
cereal rye can
damage corn
the most
Allelopathy issues
Corn must be planted 2โ deep and slot tightly closed
to reduce problem, or wait 2 weeks after killing rye to plant
31. Mature cereal rye mulch with only glyphosate
burndown- June planting
32. Corn into high residue issues
โข Cover crop removes all the nitrogen in top 12โ of
soil- soil tests show < 3#/a at cover termination
โข Requires in furrow nitrogen, and/or 50-70#/a
surface applied at planting- issue of tie up surface
applied as wellโor 30+ #/a starter
โข Early research shows cover crop nitrogen takes
temperature, moisture and time to become
available
34. New radish developments
โข 2014 there were 34 different varieties
โข Many have totally different qualities
โ Kill different nematodes or propagates nematodes
โ Michigan State University doing extensive work
โข Work starting on evaluation for soybean cyst
nematode, root knot nematode, sugar beet
nematode, corn nematodes
36. Consider cover crop strip till
โข Requires precision planting
โข Requires good GPS autosteer/RTK
โข Needs to be timely
โ Getting it planted on time is important
โข Reduce seeding rate in strip
โ Radishes 1โ1.5#/a
โ Rapeseed 3-4#/a
โข Controls winter and early weeds while
providing โbare, tilledโ row for early planting
41. Seeding on the Radish winter killed rowโnotice low residue in row
42. Establishment โearly or perennial
cover crops
โข Annual ryegrass/legumes establishment at V-6 to7
โข Seeding middles only
improves establishment and
planting crop next spring in strips
โข Use less seed
โข Increased fall growth
โข Better winter hardiness
โข Increased fall grazing
โข Improve weed control
Dr. W Curran, Penn State U.
43. Weeds
If Tillage and Herbicides controlled
weeds---
Why are we still doing it every year??
Dr. D. Beck