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An overview how cover crops can benefit soil health
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ROLE OF COVER CROPS IN SOIL HEALTH AND
OUTREACH T.M. Reinbott*, K.M. Clark, D.
Peterson*, and R.G. Hoormann
Winter Annual Legumes
Hairy VetchCrimson Clover
Summer Legumes
Sesbania Sunn Hemp
Cowpea
Important to Inoculate
Each Species of Legume has a Different Species of Bacteria
You must match them together.
Buckwheat
Very Short Growing season-60 days
Some Weed Control-Allelopathy
Inexpensive Seed-much like wheat or rye
Attract Beneficial Insects
Many uses for Vegetable production
Nutrient Cycling
Cereal Rye and Oats
Inexpensive Seed Rye is very winter hardy Spring Oats is not winter
hardy and will winter kill-can be used to our advantage
Rye tremendous dry matter
Suppress weeds Allelopathy or Blocking
Light Good to mix with
legumes
Annual Ryegrass
Plant in Fall Overwinter-most of
the time Deep Roots-5-6 ft Scavenge Nitrogen Dense matt controls
weeds Can become a
weed! Herbicide
resistance problem
Radish-Forage or Oil Seed
Late Summer Planted
Sequester Nitrogen
Loosen Soil
Weed Control?
Tillage Radish
FallSpring
Polycultures-More Diversity Above and Below Ground
Diversity of Perennial Native Grasses, Forbs, and Legumes
Desiccation of the Cover CropRoller Crimper
No-Till With Cover Crops After Crop Emergence
More To Cover Crops Than Just Nitrogen
From Steve Groff
Cover Crop
No Cover Crop
Cover Crops Reduce Water Runoff or Increase Water Infiltration
Much Better Water Infiltration Following a Cover Crop
McVay, et al. 1989,Soil Sci. Soc. Am. J
WHAT OTHER BENEFITS DO COVER CROPS HAVE?
Nutrient Scavenge, Loosen Soil, Weed Control
SOIL PHYSICAL PROPERTIES
TillageRadish®
field
Openfield
Soil compactiondecreased by >40%
Ohio State UniversityCourtesy of Steve Groff
Loosen Soil-Increase root growth and water infiltration?
Less Compaction Equals More Root Density Deeper Following Radish and Rye
Soil Physical Properties Following 3 Years of Cover Crops
Treatment Water-Aggregate Stability Pentrometer Bulk Density
% Increase over control % increaseMg/m3
Corn/Soybean 1.32 Corn/rye/soybean/rye 9 19
1.24 Corn/rye/soybean/hairy vetch 13 8
1.23 Corn/rye/soybean/Hv+rye 17 16
1.23 From Villamil, et al 2006
NUTRIENT SEQUESTRATION
Soil Nutrient Content at Various Depths on a Mexico Silt Loam
Depth pHs OM P Ca Mg K CEC Mn
Inches % lb/acre lb/acre lb/acre lb/acre meq/100g ppm
0-3 5.6 4.2 16 3393 279 170 12.4 25.2
3-9 6.0 3.2 8 4211 318 85 14 25.0
9-12 6.0 2.5 7 3513 480 136 13.5 4.3
12-18 5.4 2.4 3 5459 1262 285 23.8 0.1
18-24 4.8 2.2 1 4598 1393 340 23.7 0.7
24-29 5.1 1.6 16 5101 1525 308 24 16.2
29-36 5.4 0.9 28 3728 906 267 16.4 35.4
36-48 5.7 0.9 32 4102 1244 244 17.8 26.0
From MU Bradford-2012
After 3 years Bring Potassium Brought Up From Deeper Depths K Content, ppm Crop 0-3 inch 3-6 inch 6-12 inch None 105 b 100 ab
109 a Rye 97 b 89 c 96 ab Crimson Clr 96 b 72 d 71 c Hairy Vetch 127 a 108 a
86 bcFrom Hargrove, 1986. Agronomy Journal
100 lb N/acre Nitrogen Captured by Tillage Radish and Rye
Shoot Root Shoot N Root N Shoot N Root N Dry Wt Dry Wt Content Content After Corn lb/acre lb/acre % % lb/acre lb/acre Radish 2165 2599 1.86 1.15 39.3 30 Rye 1757 2.39 37.9
After Soybean 3345 1989 3.93 3.12 132 62 2545 3.94 100
From Dean and Weil, 2009 Journal of Environmental Quality
Radish and Rye Capture Nitrate-N in the Soil Profile
Fertilizer Phosphorus Utilization Is Enhanced When Taken Up By a Cover Crop in an Acid Soil
1 20
5
10
15
20
25
30
35
40
Triple Super Phosphate
Legume+Fertilizer
Weeks After P Application
% P
U
tiliza
ton
815
Adapted from Bah, et al, 2007
Many of These Observations are a Result of Improvement of Soil Health or Soil Quality
Cover Crop Roots Feed the Soil Microbes
Greater Crop Diversity equals greater Microbe DiversityBacteria-100 million-1 Billion!
Fungal Filaments-Several YardsProtoza-Several ThousandNematodes-10-20
Cover Crops Can Attract Beneficial Insects Including Pollinators
Cover Crops Attract Butterflies, Bee (including Bumble Bees and other Native Bees), beneficial beetles, lacewings, etc.
Outreach-Specialized Field Days, Workshops, and Clinics
QUESTIONS?