Managing Cover Crops For the 21st Century

Hairy Vetch, The Queen of Cover Crops

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

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 Sensitive to Wet Feet

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

Crimson Clover Varieties

Some New Varieties are 7-14 days earlier

Crimson Clover Days to 50% flowering Dry Matter yieldFrom February 1 lb/acre

Sunrise 51 1471Robin 58 1587Tibbee 67 1946Chief 65 1921Dixie 66 1872

Courtesy of Auburn University

Crimson Clover Reseeds Itself If Allowed to Bloom

Summer Cover Crops

Following Wheat Summer Annual

Legumes Sunn Hemp Sesbania Cowpea

Cowpea

Summer Legumes

Sesbania Sunn Hemp

Tropical Legume Yield and N

Summer Cover Crops lb/acre %N lb N/acre Sesbania 4051 1.97 79 Sunn Hemp 5097 1.87 83 Cowpea 3325 2.47 81

From MU Bradford Research Center 2012

Plant Rye Afterward To Capture the N

Important to Inoculate

Each Species of Legume has a Different Species of Bacteria

You must match them together.

NON LEGUMES

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 in Late OctoberLeft-planted August Right volunteer

0.75 lbs5.75 lbs

Radish

FallSpring

WHAT BENEFITS DO RYE, RYEGRASS, AND

TILLAGE RADISH HAVE?Nutrient Scavenge, Loosen

Soil, Weed Control

Tillage Radish Root dug out-32”Courtesy of Steve Groff-Pennsylvania

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

NUTRIENT SEQUESTRATION

Soil Nutrient Content at Various Depths

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 ppmCrop 0-3 inch 3-6 inch 6-12 inchnone 105 b 100 ab 109 aRye 97 b 89 c 96 abCrimson Clover 96 b 72 d 71 cHairy Vetch 127 a 108 a 86 bc

From Hargrove, 1986. Agronomy Journal

Nitrogen Capture Tillage Radish and Rye

Rye and Radish can capture 100 or more lbs/acre of N

Shoot Dry wt Root Dry Wt Shoot N Content Root N Content Shoot N Root NAfter Corn lbs lbs % % lbs lbsRadish 2165 2599 1.86 1.15 39.3 30Rye 1757 2.39 37.9

After SoybeanRadish 3345 1989 3.93 3.12 132 62Rye 2545 3.94 100

From Dean and Weil, 2009 Journal of Environmental Quality

Radish and Rye Capture Nitrate-N in the Soil Profile

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 $0.72/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

Polycultures

Polyculture Seeding Rate

Divide monoculture seeding by number of species:

Ex) Hairy Vetch-30 lb/acre, Cereal Rye-90 lb/acre, Austrian Winter Pea-60 lb/acre in monoculture

When mixed: Hairy Vetch-10 lb/acre, Cereal Rye 30 lb/acre, and Austrian Winter Pea-20 lb/acre

Polycultures

Polyculture Before Harvest

ESTABLISHMENT AND GROWTH

Herbicide Carryover Potential

Table 1. Typical herbicide rates, sensitive species, half- life, and potential for carryover injury to sensitive crops (carryover potential based on half lives and soil availability). Herbicide half-life estimates derived from the WSSA Herbicide Handbook, 2007 or other scientific literature.

Herbicide Typical rate/acre Sensitive species Half life (days) Carryover potential

Accent 2/3 oz brdlfs+grass 21 Low

Assure/Targa 8 oz grass 60 Low

Atrazine 1 lb brdlfs+grass 60 Moderate

Authority 4 oz brdlfs 32-302 Moderate

Balance Pro 2 fl oz brdlfs+grass 50-120 Moderate

Callisto 6 fl oz brdlfs 5-32 Moderate

Classic 2 oz brdlfs 40 Moderate

Dual II Mag 1.67 pt brdlfs+grass 15-50 Low

FirstRate 0.33 oz brdlfs 8-33 Low

Harmony 1/8 oz brdlfs 12 Low

Harness 2 pt brdlfs+grass 10-20 Low

Impact 0.75 fl oz brdlfs+grass 14 Low

Laudis 3 fl oz brdlfs+grass 14 Low

Outlook 16 fl oz brdlfs+grass 20 Low

Peak 1 oz brdlfs 9-152 Moderate

Permit 2/3 oz brdlfs 9-27 Low

Prowl H2O 3 pt brdlfs+grass 44 Low

Pursuit 4 fl oz brdlfs+grass 60-90 Moderate

Raptor 5 fl oz brdlfs+grass 20-30 Low

Reflex 1.5 pt brdlfs 100 Moderate

Resolve 2 oz brdlfs+grass 2-4 Low

Select 10 oz grass 3 None

Sencor 0.33 lb brdlfs+grass 14-60 Low

Sharpen 3 fl oz brdlfs 7-35 Low

Simazine 1 lb brdlfs+grass 60 Moderate

Stinger 5 oz brdlfs 40 Moderate

Valor 2.5 oz brdlfs 12-20 Low

Inter Seeding Annual Ryegrass into Corn

Interseeding

Establishment-Drilled After Soybean or Corn

Alternative: Corn And Soybean Planter

Cover Crops in 15 inch rows

Alternating 15 inch Rows

ALTERNATIVE PLANTING MIXES

Planted Radish With Broadcast Ryegrass

8/25/12 10 lbs./ac. Ryegrass broadcast8/27/12 5 lbs./ac. Radish planted10/19/21 Photos

Ellis and Hoorman, 2012

Tillage Radish and Ryegrass in November 2012. Hoorman and Ellis

And Now, January 2013

UTILIZING THE 15 INCH ROW PLANTER

Polyculture in the Spring

Sunn Hemp and Tillage Radish In the Summer

Steve Groff in Pennsylvania

Sunn Hemp and Tillage Radish After a Frost

Steve Groff Pennsylvania

Bio Strip-tillRadish and Ryegrass in the Early Spring

Steve Groff, Pennsylvania

Bio Strip-tillSpring, Steve Groff

Plant Into the Radish and Then Kill the Ryegrass

COVER CROPS IN THE FALL, WINTER, AND

SPRING

Mixes With Legumes/CerealsEarly September Compared

to Late October

January 2012

Cereal Rye and Hairy VetchOverseeded into Corn on September6th 2011

Oats and Hairy Vetch OverseededInto Corn on September 6th 2011

January 2012

Crimson Clover overseeded intoCorn on September 6th 2011

Crimson Clover drilled into soybeanResidue on October 12

January 2012-Tillage Radish

Spring GrowthEarly May-Typically

1200-1500 lbs/acre 2,000 lbs/acre

Mixes in Late May

2-5,000 lb/are depending upon the year

When and How Do You Kill The Cover Crop?

Herbicide Effectiveness on Cover Crops

Courtesy of Penn State Extension, 2012

chop roll chop roll chop roll chop rollbefore cc destroyed same day cc destroyed 1 week after cc

destroyed2 weeks after cc

destroyed

0

10

20

30

40

50

60

70

80

90

100

Corn germination when planted into rye cover crop

Pla

nt

count

per

10 f

eet

From MU Bradford Research Center, 212

When Do You Plant? Plant Population Decreases As You

Delay After Dessication

Planting Into a Standing Crop

Desiccation of the Cover CropRoller Crimper

After Roller Crimper

Flail Chopper or Mower

To Roll or Flail Chop

DAY OF DESICCATION 5 DAYS LATER

Flailed Rolled Rolled Flailed

What If The Cover Crop Is Still Alive?

PLANT PERPENDICULAR TO THE WAY IT WAS ROLLED

SEED TO SOIL CONTACT CAN BE A CHALLENGE

What If You Don’t Have a Roller Crimper? Cultipacker?

NITROGEN BENEFIT

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

% N Remaining Over TimeFrom Wagger, 1989, Agronomy Journal

Harvest Time on N and C:N Ratio

Cover Crop Harvest Time Dry Wt N ConcentrationTotal N C:Nlbs/acre % lbs/acre

Rye Early 6355 1.49 94 27:1Rye Late 8144 1.25 101 32:1Crimson Clover Early 3827 2.76 106 14:1Crimson Clover Late 5260 2.48 131 16:1Hairy Vetch Early 3720 3.69 131 11:1Hairy Vetch Late 6337 3.22 204 12:1

From Wagger, 1989. Agronomy Journal

More To Cover Crops Than Just Nitrogen

Missouri Data-Bradford

From Reinbott, et al, 2004. Agronomy Journal

May Corn Grain SorghumMissouri 1997-1999Cover Crop Cover Crop Fertilizer N Fertilizer NCover Crop Seeding rate Dry Matter Equivalent Equivalent

lb/acre lb/acre lb/acreHairy Vetch 30 1744 37.3 54.8Hairy Vetch 20 1451 40.2 46.5Austrian Winter Pea 60 712 26.4 35.1Austrian Winter Pea 40 757 33.6 6.5HV+Oat 30+90 1197 28.5 40.9HV+Oat 20+90 1059 18.6 21.7AWP+Oat 60+90 990 -24.2 15AWP+Oat 40+90 481 -16.8 -3.6Oat 90 0 -24.5 -4.2

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

Centralia 88-Acre Research Field

1991-2003 CORN-SOYBEAN MULCH-TILL 2003-2012 NO-TILL + COVER CROP

Soybean-Wheat

Soybean-Corn

Centralia 88-Acre Research Field

Centralia 88-Acre Research Field

What Is Causing This?Soil Health With Cover Crops

Better Water Infiltration

Nutrient Cycling

Root Development

In One Teaspoon of A Healthy Soil

Bacteria-100 million-1 Billion!

Fungal Filaments-Several Yards

Protoza-Several Thousand

Nematodes-10-20

WEED CONTROL

Winter Annual Weed Control with Rye and Tillage Radish in Maryland

From Lawley, et al, 2011. Agronomy Journal

TillageCereal

Time No Cover Radish Rye % Late Fall 96 0 0 Late March 99 3 1 Late April 75 37 0

A Thick Mulch

Weed Control from Cover Crops in Pennsylvania

Cover Crop Broad Grasses Peren.Total

2007 Number/ft2

Hairy Vetch 1.2 2.1 6.8 10.4 None 1.8 8.0 9.9 20.1 2008 Hairy Vetch 0.7 0.7 0.6 2.0 None 5.1 6.3 0.9 12.3 From Mischler, et al 2010 Agronomy Journal

Soybeans Following Rye or Legumes With Only Glyphosate Applied Two

Weeks After Planting

Potential Rotations

Corn/Soybean Corn/rye/Soybean/radish+oats Corn/rye+legume/Soybean/polyculture including

legumes Corn/Corn-plant early

Overseed oats+radish or oats+radish+crimson clover

Corn/Soybean/Wheat Similar to above except after wheat follow a

tropical legume such as sunn hemp, cowpea, and then other cover crops in the fall

QUESTIONS?