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?