Daniel Brainard Carolyn Lowry Ben Henshaw

Michigan State University Department of Horticulture

March 2012

Integrating reduced tillage and cover crops for organic vegetable production

Figure 1. Winter rye residues in reduced-­‐tillage snapbeans can helps suppress weeds, retain moisture, andprotect the soil.

Strip tillage

Strip Tillage and Cover Crops!

Untilled BR Zone!• Soil moisture retention!• Soil erosion protection!• Reduced splashing!

• Habitat for beneficials!

Tilled IR Zone!• Warmer!

• Higher mineralization!• Good seed bed!

Adapted from John Luna

. . . . . .

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Dead mulch

Living Versus Dead Mulch

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Living mulch

Adapted from John Luna

Living Mulches

Strip-tillage in Carrots Plant wheat (fall) or barley (April) Strip-tillage and carrot planting in May Kill wheat or barley once carrots are established

Living mulch as wind break for carrots

Early spring winter rye

Strip-tillage

July

August

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Benefits: Erosion protection

Benefits: Reduced soil splash & fruit staining

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Benefits: Beneficial Insects

Bryant and Szendrei unpublished

Image adapted from: http://www.swac.umn.edu/classes/soil2125/img/8drprg2.jpg

Year 1

Year 2

Year 3

Sub-surface Drip and Strip Tillage

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Conventional tillage

Strip tillage

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Challenges: Weed Suppression

Weeds often more abundant in reduced tillage Cover crop residue can help suppress weeds under reduced tillage

Challenges: Cover Crop Regrowth and Weeds

Hairy vetch: Friend or Foe?

Pros •  Grows off-season •  Fixes lots of Nitrogen

Cons •  Re-growth potential •  Can winter-kill •  Expensive seed

Cover crop N (lb/A) Red Clover 50-120

Crimson clover 30-60

Hairy vetch 50-100

Austrian Winter Peas 30-70

Cowpea/Soybean 40-100

Approximate N contribution of legumes

Hairy vetch: Research MSU

Variety trials (Henshaw/Snapp) •  Early flowering •  Winter hardiness •  Compatibility with rye

Mixtures •  Proportions (Hayden) •  Placement (Lowry)

1.  ‘Oregon’ vetch 2.  ‘Purple Prosperity’ vetch 3.  ‘Purple Bounty’ vetch 4.  Oregon + rye 5.  P. Prosperity + rye 6.  P. Bounty + rye

Vetch variety and mixture trial Treatments (Ben Henshaw)

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Hairy vetch Flowering Timing

“Early flowering” varieties flower

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Mixtures with rye result in earlier

flowering

Earlier flowering means easier to kill

N to crop not weeds Minimize vetch re-growth Minimize rye interference

Lower seed costs

Segregated Cover Crop Strips (Carolyn Lowry)

Segregated Cover Crop Strips

Acknowledgements •  MSU Project GREEEN •  Michigan Vegetable Council •  South West Michigan Research and Extension Center •  C. S. Mott Group for Sustainable Food Systems •  The Ceres Trust •  NC-SARE

•  Corey Noyes •  Ron Goldy •  Dave Francis •  Bill Steenwyk •  Dave and Ken Miedema •  Bill Chase

•  Sieg Snapp •  Erin Haramoto •  Zsofia Szendrei •  Alex Bryant •  John Teasdale •  Zack Hayden

•  Norm Myers •  John Bakker •  Steve Dillingham •  Robin Bellinder •  Andy Miller •  Steve McKay

Rye-vetch mixtures N content by source

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20

40

60

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100

120

140

160

180

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N content = 40-140 lbs N/acre

Nitrogen Fertilizer Replacement Value=

20 - 70 lbs N/acre

Approximate cost of N fixed=

$ 0.41 – 1.42 lb