weed management for organic soybeans

Organic weed management for soybeans

Joel GruverWIU Agriculture

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

Adapted from Bailey and Lazarovits (2003)

Organic weed management

Crop

3 broad goals of ecological

management

Activation

AugmentationConservation

Suppression

A nice flush of weeds ready for termination

What can we do to maximize this flush?

Not all tillage operations have the same effect

Terminating spring planted oats with a soil finisher~ 3 weeks before planting corn

GOAL = biological activation and suppression

Are you familiar with the fence post principle?

Zone of maximum biological activity and rapid residue decay

Deeper burial does not optimize decay but sends weed seeds into deep dormancy and brings deeply dormant

weed seeds to the surface where they germinate slowly

Who is sleeping in your soils?

Do any of you have experience with flame weeding?

Dennis Leutke in MN and Larry Shrock in MO are experts

Terminating weeds without awakening sleeping seeds

No pre-plant tillage for this experiment

Ridge till and No-till soybean strips

will require no pre-planttillage this spring

Effectiveorganic weedmanagement

Integration of many little hammers

No one hammer is likely to provide acceptable weed control

=

Cropping system strategiesvs.

Direct control strategies

Effective strategies disrupt weed life cycles

Cropping system strategies

Crop rotationTillage rotationCover cropping

Crop managementFertility managementManure management

Field/equipment/seed sanitation

Optimize crop establishment to maximize crop competitiveness

-Select a well adapted variety (maximum leafiness and rate of canopy closure)

-Delay field work (soil must be warm enough for rapid crop emergence)

-Prepare a good seed bed (start out clean)

-Reduce row spacing and increase populations

-Row fertilizer?

Preventive management

• Flush soil seed bank with fallow periods

• Walk crops

• Employ alternative equipment for mowing, pulling weeds

• Weedy crops -> forage or cover crops

ABCs of mechanical andcultural weed management

Page 11 – Steel in the Field

A. Give the crop the advantage.

B. Keep weeds on the defensive.

C. Accept weeds that don’t really matter.

Excellent reference describing equipment for direct control of

weeds

Blind cultivation normally occurs before

the crop emerges or shortly after emergence

Blind cultivation

30’ rotary hoe

Are you getting full performance out of your rotary hoe?

Rotary hoes and flex-tine weedersare most effective when the soil has a crust

Some crop damage is inevitable but care should be taken to avoid times when crop is most fragile

Inter-row cultivation

Guidance systems are available to increase accuracy and reduce operator

stress during cultivation

Innovative farmers have developed a wide range of cultivation tools

Fall planted small grains are very competitive against weeds

Do you see a cover crop?

Do you see a cover crop?

Frost seeded clover

the most tried and true cover cropping system in the Midwest region

Sweet clover

Mustard

Frost seedingoptions

We are going to try frost seeding mustard for the

first time this spring

Klaas and Mary Martens, organic innovators in Central

NY State, are reporting excellent results with frost-

seeded confectionary mustard ahead of dry beans

Where are the soybeans??

Traditional organic weed management often comes up short during wet years

A strong stand of cereal rye was incorporated ~ 2 weeks before these soybeans were planted

Pioneering work by Jeff Moyer at

the Rodale Institute

has sparked considerable

interest across the country

Innovation all across the US

Mechanical innovation is key to making

conservation tillage systems work

September October

November January

Tillage System Experiment at the WIU organic research farm

March April

Early May Late May

Options for rolling cover crops

Rodale design

Cultimulcher

Early June

1 week later

~2 weeks after planting

July

August late September

Early November

Plot yields ranged from 51.6 to 58.6 bu/ac

No significant differences between systems

November 2010

Plot yields ranged from 42-52 bu/ac

Significant foxtail pressure but almost no broadleaf weeds

Bio-strip till

September 2008

Early September 2009

Tillage radish on 30” rows with oats on 7.5” rows

Early November 2009

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

S. Carruthers

Radish planted in volunteer cereal rye

November 2010

Wheat + radish trial November 2010

July 17 planting

July 29 planting

Weed management for organic row crops

Weed management for organic row crops

I recently received a grant to support documenting the weed management practices

used by top-notch organic weed managers

How should we go about finding top-notch organic weed managers?

What questions should we ask them?