overview of cover crops in relation to soil and nutrients

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?