overview of cover crops in relation to soil and nutrients
DESCRIPTION
An update on the research at the MU Bradford Research Center on Cover Crop ManagementTRANSCRIPT
USING COVER CROPS AS A SOIL MANAGEMENT TOOL
Wind Erosion
Water Erosion
Soil Erosion-Even With No-Tillage
100+ Years of Tillage
Tilled VS No-Till-We have lost nearly 1 ft of top soil
LONG TERM PASTURE TILLED IN A CORN/SOYBEAN/WHEAT ROTATION
The Evils of Tilling-Whether It Is a Plow or a Field Cultivator
Loss of Organic Matter Soil structure Soil microbial
biomass Release of CO2
Soil Erosion
Why Till? Weed Control
Organic Matter
This is what separates us (Missouri) from Central Iowa, Illinois, Minnesota, Indiana, etc
In these areas climatic conditions favor the accumulation of Organic Matter Slower breakdown,
long history of deep rooted native perennial plants
What Does Organic Matter Do?
Nutrient Cycling Nutrient Holding Capacity Pool of Nutrients Food for soil organisms
Water Dynamics Improves water infiltration Improves water holding
capacity Structure
Reduces crusting, compaction, erosion
Encourages root development
Loss of Organic Matter and Loss of Soil Structure
Micro Organisms: In One Teaspoon of A Healthy Soil
Bacteria-100 million-1 Billion!
Fungal Filaments-Several Yards
Protoza-Several Thousand
Nematodes-10-20
Slake Test
What Holds All of This Together? Fungi Hyphae
Most Microorganisms Are In The Top 7”
The Decay Zone
Need To Feed The Soil Year Around-1200 lbs/acre of Soil Microbes
Active Carbon in Soil Organic Matter
Courtesy Brady and Weil, 2012
Active Carbon
CAN COVER CROPS BE THE ANSWER?
LegumesSoybeans, Clovers, Alfalfa, Locust Trees!
Nodules-Symbiotic Relationship Between the Plant and the Bacteria. Atmospheric Nitrogen is Fixed by the Bacteria For Use by the Plant.
How Do You Know A Nodule Is Fixing Nitrogen?
Important to Inoculate
Each Species of Legume has a Different Species of Bacteria
You must match them together.
Hairy Vetch, Queen or Beast?
A lot of biomass-2-3 tons/acre
Winter Hardy High Nitrogen Fixation-
100 plus lbs/acre Wide window of
planting August-mid October March Hard Seed, late
maturing Problem When Wheat
is in the Rotation
Timing of Hairy Vetch Harvest and Corn Yield
Adapted from Gallagher, Penn State
2007 Hairy Vetch Corn Yield-0 NTime lbs/acre %N N lbs/acreEarly (May 4) 1,400 3.82 55 113Middle (May 15) 4,300 4.43 190 132Late (May 31) 6,600 4.15 274 140
2008Early (May 1) 3,204 2.49 80 92Middle (May 14) 4,005 2.92 117 121Late (May 29) 4,361 4.55 197 79
Hairy Vetch-in Mid MO
Early May Late May
Austrian Winter Pea
Large Biomass High N fixation-80-
120 lbs/acre Plant fall or early
spring Not as winter hardy
Seedling Disease problems
Austrian Winter Pea at Maturity
Crimson Clover
Plant August-September
Early spring maturity
Not as much biomass as Hairy Vetch or Peas
Can reseed themselves
Crimson Clover
NON LEGUMES
Cereal Rye
Inexpensive Seed Rye is very winter
hardy Rye tremendous
dry matter Suppress weeds
Allelopathy or Blocking Light
Good to mix with legumes
Oats
Spring or Winter Spring planted in
the fall will winter kill
Quick Growth in the Fall
Great Companion Crop
Triticale
Cross between wheat and cereal rye
Hardiness of cereal rye
Good forage potential
Does not have the allelopathic potential as cereal rye
Annual Ryegrass-DO NOT USE!
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
Tillage Radish-Small Roots Go Down Deep!
How About Forage Value?
Mean Forage Nutritional AnalysisFrom November-June
Species Crude Protein ADFNDF
%
Arrowleaf clvr 24.9 ab 21.5 bc 26.0 cd
Field Pea 23.2 b 21.4 bc30.2 c
Cereal Rye 19.1 c 25.1 a46.4 a
Ryegrass 19.1 c 24.7 ab41.8 b
Hairy Vetch 26.4 a 19.7 c25.1 d
Summer Cover Crops
Following Wheat Summer Annual
Legumes Sunn Hemp Sesbania Cowpea
Cowpea
Summer Legumes
Sesbania Sunn Hemp
WHAT BENEFITS DO RYE, RYEGRASS, AND
TILLAGE RADISH HAVE?Nutrient Scavenge, Loosen
Soil, Weed Control
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
Gruver, et al, 2012
Soybean Roots Follow Cover Crop Root Channels
Williams and Weil, 2004
NUTRIENT SEQUESTRATION
Percent Total Available P and K at Different Depths in the Soil Profile-Silt
Loam-Silty Clay Loam
P K0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
36 to 4829 to 3624 to 2918 to 2412 to 189 to 123 to 90 to 3
Clark and Reinbott, 2012
Soil Potassium Levels After Three Years of Cover Crops
0 to 3 3 to 6 6 to 120
20
40
60
80
100
120
140
noneRyeCrimson CloverHairy Vetch
lb K
/acr
e
Hargrove et al, 1986
Increase in Soil Test P Around Tillage Radish Roots by 2X
1.25 inch
2 inches
White and Weil, 2011
Nitrogen Capture By Tillage Radish
-10
10
30
50
70
90
110
130
150
Shoot
RootCornCorn
Soybean
Soybean
Lbs/
acr
e
Dean and Weil, J Eniv. Quality 2009
Radish and Rye Capture Nitrate-N in the Soil Profile
NITROGEN BENEFIT
More To Cover Crops Than Just Nitrogen
N Release over Time From Cover Crops in North Carolina
2 4 8 12 160
10
20
30
40
50
60
70
80
90
100
Rye
Crimson Clover
Hairy Vetch
From Wagger, 1989. Agronomy Journal
lbs/
acr
e
Weeks
Benefits Other Than Nitrogen?
Weed Control Smothering or
Allelopathy Soil Health
-soil microbes If no-till: soil and
water conservation
From Steve Groff
Cover Crop No Cover Crop
Cover Crops Reduce Water Runoff or Increase Water
Infiltration
Water From Tilled (left), No-Till (middle) and No-Till With Cover Crop (right)
Utilizing Cover Crops
Using Tillage Radish In 15 inch rows
In the Spring
Planting Soybeans Into Standing Crop in Mid May
Corn Population Rolled First vs. Planting Into Standing
27,427
25,606
Results From Using Cover Crops
7 more Bushels/acre
Seed Cost-$45/acre
7 bushel/acre @ $13/bushel=$91/acre
Or about $46/acre profit
Corn Yield From Kentucky
0 50 1000
20
40
60
80
100
120
140
160
Hairy Vetch Crimson Clover
Rye Control
187 lb N/acre
50 lb N/acre
36 lb N/acre
From Ebelhar et al, 1986
2013 Soybean Yield After Cover Crops
Soybean Yield 2013 Cover Crops Overseeded into Corn Sept. 2012 Treatment Yield Bu/acre Control 29 Hairy Vetch 24 Crimson Clover 28 Radish 27 Cereal Rye 36 Hairy Vetch+Rye 28 Crimson Clv. +Rye 33 Radish + Rye 29 Rye+Radish+HV+CC 27
Reinbott, 2013
2013 Corn Yield After Cover Crops
Corn Yield 2013 Cover Crops Overseeded into Soybean September 2012 Corn Treatment Yield Bu/acre Control 175 Hairy Vetch 199 Crimson Clover 165 Radish 174 Cereal Rye 175 Hairy Vetch+Rye 187 Crimson Clv. +Rye 181 Radish + Rye 173 Rye+Radish+HV+CC 174
Reinbott, 2013
Not As Much Yield Advantage As It Looked
ECONOMICSBrief
Seed Costs
Hairy Vetch-$2.0/lb or $40-60/acre Austrian Winter Pea-$0.73/lb or $29-
44/acre Crimson Clover-$1.2/lb or $24/acre Radish-$4 lb or $32/acre Cereal Rye-$0.23 or $14-21/acre Annual Rye-$0.80 or $16/acre Sunn Hemp-$2.5/lb or $50-75/acre Sesbania-$2.4/lb or $48/acre
Cost of Nitrogen per PoundAmmonium Nitrate is $0.65/lb
Hairy Vetch-$40@ 100 lb N/acre=$0.40/lb
Austrian Winter Pea-$29@80 lb N/acre=$0.36/lb
Crimson Clover-$24@75 lb N/acre=$0.32/lb
Sunn Hemp-$50@80 lb N/acre=$0.62/lb
Sesbania-$48@80 N/acre=$0.60/lb
QUESTIONS?