cover crops for organic field crops in mn

Joel Gruver WIU- Agriculture

J-gruver@wiu.edu (309) 298 1215

Cover crops for organic field cropping systems in MN

http://www.slideshare.net/jbgruver/

Almost 500 miles!

Macomb

Macomb IL Apr 21 Oct 11 180

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Historically, 29% more GDD @ 40F

than Saint Cloud

Very few opportunities for CC before or after corn and soybeans

http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Annual_Statistical_Bulletin/2011/Whole%20Book.pdf

Many more opportunities for CC after wheat, barley, oats, rye, peas…

http://www.nass.usda.gov/Statistics_by_State/Minnesota/Publications/Annual_Statistical_Bulletin/2011/Whole%20Book.pdf

small grains + warm season grasses + a. ryegrass + buckwheat + flax

mustard + radish + rapeseed/canola + turnip

alfalfa + clovers + vetch + peas + soybeans

6 mixtures of c. rye, a. ryegrass, c. clover, oats, radish, peas + vetch

Crop planted on 5/15

and harvested

on 10/1

Crop planted on 4/15

and harvested

on 8/15

MCCC website also provides links to lots of good extension publications

Lots of potential cover crop species are described in this publication

Wisconsin data suggest that approximately 70% of whole-plant N will become available in the first year following clover, most released before corn begins its

period of rapid uptake.

Usually, the best conditions for frost seeding occur in mid to late March. Low overnight temperatures cause the surface to freeze

and crack. Warm daytime temperatures thaw the surface, sealing the cracks. If daytime thawing occurs, the daily “window” for

seeding lasts only a few hours, beginning at dawn. With subfreezing daytime temperatures, seeding can occur anytime

during the day. Seed can be broadcast until mid-April if cracks are present and the traditional frost-seeding window is missed.

Gary Sommers’ farm in Clinton, Wisconsin, is just down the road from his boyhood home. He grows corn, soybeans, and winter wheat on 1,475 of his 1,500 acres. The remaining 25 acres are enrolled in the Conservation Reserve Program. Gary mainly uses cover crops on his steeper fields. Usually he sows cover crops—including buckwheat, soybeans, oats, and Berseem clover—after harvesting winter wheat in mid-July. The following spring he plants these fields to corn. Cover crops which do not winter-kill are terminated in the fall to prevent corn planting delays.

Grazing brassicas, clovers, alfalfa, small grains, annual ryegrass, sorghum-sudan

Nutrient scavenging/cycling brassicas, small grains, annual ryegrass

Bio-drilling brassicas, annual ryegrass, sugarbeet, sunflower,

sorghum-sudan sweet clover, alfalfa

N-fixation clovers, vetches, lentil, winter pea, chickling vetch, sun hemp, cowpea, soybean

Bio-activation/fumigation brassicas, sorghum-sudan, sun hemp, sesame

Weed suppression brassicas, sorghum-sudan, cereal rye, buckwheat

GRAZING = #1 way to make cover crops pay!

Match CC objectives with species

Oats, turnips, annual ryegrass and wheat

Oats, turnips and cereal rye

Forage kale

Mystery brassica

On farms with livestock, many failures can be turned into success!

Cover crops (winter or summer) can provide high-

quality forage and increase economic return and farm diversity, but some farmers have been reluctant to take this advantage due to perceived “compaction” caused

by animal trampling.

Grazing of cover crops can compact soil, but not to the detrimental levels often perceived.

Franzluebbers AJ and JA Stuedemann. 2008. Soil physical responses to cattle grazing cover crops under conventional and no tillage in the

Southern Piedmont USA. Soil and Tillage Research 100, 141-153.

Crop Rotation on Organic Farms: A Planning Manual provides an

in-depth review of the applications of crop rotation-including

improving soil quality and health, and managing pests, diseases, and

weeds. Consulting with expert organic farmers, the authors share

rotation strategies that can be applied under various field

conditions and with a wide range of crops.

Crop Rotation on Organic Farms is most applicable to farms in the Northeastern United States and

Eastern Canada but is worth a look

Start planning today!

• Anticipate planting windows • Match objectives with species

• Confirm seed availability • Make sure seeding equipment is ready • Identify realistic termination methods

• Allocate labor • Develop contingency plans

When can you plant CCs?

• Dormant seeding early or late winter

• Frost seeding

• In the spring

• In the spring w/ cash crop

• Prevent plant scenarios

• At last cultivation

• After small grains

• After vegetables

• After seed corn or silage corn

• Aerial or high clearance seeding into standing

crops in late summer/early fall

• After long season crops

What is this CC?

Phacelia

WIU Organic research farm – May 2012

Very dense rooting at the

soil surface

Mustard variety trial at the Allison farm in early June 2011

Pacific Gold Ida Gold

Slower to mature Faster to mature

More biomass Less biomass

JD 730 Air-Disk drill on Jack Erisman’s farm in Pana, IL

Jack uses this rig to drill soybeans on 6" rows (~ 280,000/ac) while also dropping ~2 bushel of rye and

some micronutrients

Zumbrun Farm Northern Indiana

Drilling cover crops after small grain harvest

There are many options other than drilling

Magness Farm in Maryland

Slurry seeding

What is PRECISION COVER CROPPING??

1) Planting of cover crops with a precision planter

2) strategic placement of cover crop rows in relation to other cover cover rows and/or the following cash

crop rows (often using GPS guidance)

3) Strategic placement of cover crops in specific fields or parts of fields

4) Selection and management of cover crops to

achieve specific objectives

Precision planting

http://www.extension.org/pages/64400/radishes-a-new-cover-crop-for-organic-farming-systems

Insecticide boxes can be used for metering small seeds

Joe Rothermel’s new rig

Cover crops planted with insecticide boxes while stripping

September 2008

Radish planted on 30” rows using small milo plates in mid-August 2010

Attempt #3

Cover crop system Relative

corn yield

Volunteer oats 79%

Radishes planted on 30” 99%

Radishes drilled on 7.5” 91%

Corn following cover crop experiment (2011)

Corn planted directly over radish rows

May 2012

Radish planted on 30” rows with RTK guidance on August 29th right before Hurricane Isaac rolled in

4 days later

7 days after planting

10 days after planting

~ 1 month later

Why are the inter-rows so clean?

We had just cultivated the radishes!

~ 2 weeks later

December 2012

We are planning to “freshen” the radish rows with a Yetter strip till bar before planting corn

directly over the radish rows

Precision planted radishes w/ peas from 5 ft of row

Precision radishes w/o peas

What is the optimal seeding rate for precision

planted radishes?

4-6 seeds per foot is probably often the best ROI but ~16 seeds per foot produced

the most biomass for us this fall

higher is probably better the later you plant

Radishes in fall 2011

~ 20 more bushels/a where we cultivated in the fall

Ridges with dead radish residues

in spring 2011

Planting popcorn on radish ridges

in May 2011

Planted beautifully but we decided to

replant after a month of relentless

rain :-<

Fall 2011

Fall 2012

Crimson clover

Chick peas

Green lentils

Fava beans

Sunflower

Rapeseed

Oats

Phacelia

We are trying to identify the best combinations of winter hardy

and winter-kill CCs for row and inter-row positions

+20 lbs N/a

A little extra N can make a big difference

Radish biomass = 2X

Preceded by spring planted radish

5 buffer rows were not preceded by a CC

Same planter pass

Most years the extra transpiration would probably have been helpful

on this wet farm

Last summer, we undercut our small grain stubble using a no-till cultivator and a tractor with RTK guidance

Fallow strip Cover crop cocktail no-till drilled after

undercutting

Triple S mix Sunflowers, Soybeans & Sunnhemp

Effective multi-tasking or cover crop chaos???

http://greencoverseed.com/

Planting into poorly digested red clover residues

25-50% stand loss Near perfect stands in all other corn

plots on the farm this past spring

Annual ryegrass after chisel plowing

Chisel plowing made the next pass with a rotavator easier and more effective

Early June 2011

No-till drilling soybeans into standing rye

15’ wide roller built by a local farmer

Mid-June 2011

Rolled after drilling

Early July 2011

Our conventional-till beans are looking good, right?

August 2011

November 2011

The NT bean plots yielded ~10 bu more than the best

tillage system plots

April 2012

In our experience, a strong stand of rye is critical

Planting into 5-6’ tall rye on May 11

Double drilled with 4” offset

June 2012

All of July :-<

Our 2012 NT bean yields ranged from ~ 30 to ~ 60 bu/a

Better drained areas of the field yielded poorly

Wet hole yielded very well

Cover Crops

Adapted from Magdoff and Weil (2004)

CCs affect many agronomic factors simultaneously

Feed livestock

Control erosion

? ?

Increase management

Host pests

Become a weed

Prevent soil drying

Dry out soil excessively

Interfere w/ equipment

performance Suppress crop

growth

Tie up N

Add cost

Cover Crops

Adapted from Magdoff and Weil (2004)

Not all effects are positive

Greater precision in your cover cropping practices will increase the

likelihood of intended outcomes

More positive and fewer negative effects

I wish you all success in 2013!