Dealing with Weeds
on a CSA Farm
Scotch Hill Farm, Brodhead, Wis.
Including SARE Farmer Rancher grant projects with Rock County UW
Extension Service & Wisconsin Department of Natural Resources
Contact: Dela Ends dela@scotchhillfarm.com
Tony Ends, tony@scotchhillfarm.com /608 897-4288
Primary Reasons to Place
Emphasis on Weed Control
Your Pocketbook
2011 forecasts for specialty crop growers expect average net cash income will
decline. Receipts will increase 4 percent; expenses will rise 9 percent.
Your sustainability
Global oil production has peaked. Fuel prices – and everything dependent on fossil
fuel – are only going to rise. Farm fuel and fertilizer costs this year rose 24 percent
each.
Your legacy
Rolled plastic from polyethylene film to mulch vegetables and fruits has helped
control weeds since the 1950s. By 1999, it spread globally to more than 30 million
acres. Much of it ends up in landfills, which are closing. Consumers worry black
plastic mulch leaches.
Your model
About 18,000 U.S. vegetable and melon farms direct market, a 97 percent increase
over 10 years. The number of CSA vegetable growers has risen from 2 in the 1980s to
more than 4,000 today. Local food production is a permanent trend, and these
growers are going to need sustainable methods that do not depend on nonrenewable energy.
Climate and Weather
Influences
Financial Ability to
Acquire tools or
equipment
Simple commercial-grade tools
are a good investment, like this
stirrup hoe
Cobra Hoe {center}
Short- or Long-Handled
Makes weeding narrow rows
easier
Heavy Duty Rogue Hoe
(second from right)
Modern Wheel Hoe
• With oscillating hoe attachment
• And hilling attachment (background)
Labor for laying mulch or for
weeding?
Why is straw mulch important?
Why should all specialty crop farmers use it, try it,
experiment with it?
Black Plastic Mulch – Pros and Cons
Easy to lay with a used $450 machine in spring; a
long, cold tiresome process to remove in late fall,
early winter
Small Grains Straw Mulch – Pros and Cons
Brussels Sprouts in switch grass mulch
No incidence of plant disease in prairie grass mulch;
both wheat and oat straw hosted some plant disease
Field Trial Comparison
at Scotch Hill Farm
Mulch materials at
application, June 2, 2010.
Top Left: Wheat straw
Bottom Left: Oat straw
Right: Prairie grass
Table 1. Chemical composition of mulch materials.
Material
N
P
K
%
%
%
Prairie grass
1.06
0.09
0.58
C
%
46.7
C:N
Ratio
44:1
Oat straw
0.58
0.22
2.30
45.8
79:1
Wheat straw
0.52
0.11
0.61
45.7
88:1
Table 2. Weed density 40 days after application
Weed
Volunteer
Material
Density
Height
Density
(p/ 2.5 ft2)
(p/ 2.5 ft2)
in
Prairie grass
10.6
var
Dominant species
Foxtail
Smallflower galinsoga
Oat straw
7.3
var
7.3
Volunteer oat
Smallflower galinsoga
Wheat straw
6.3
var
min
Foxtail
Smallflower galinsoga
Var, variable. Different species present in differing densities made calculating
an average height meaningless.
Min, minimal. Less than one plant per sample
Prairie (switch grass) Mulch – Pros and Cons
Seed sown 5 lbs. to the acre; takes 2 to 3 years to establish;
must be managed (mowing several times first seasons,
controlled burn in fall to increase vigor and suppress weeds)
Specialized Equipment for Switch Grass
Truax812 planter, Circa 1978 for fine native
species seed varieties
Establishing a field of switch grass
Seed drill on loan from Wisconsin Department of
Natural Resources
Two-year Comparison
• Used all 3 mulch types in 12 crops
• Conduced field trial with tomatoes
(high traffic) and Brussels sprouts
• Observed weed suppression
• Estimated organic matter rate of
decomposition and availability to soil
• Watched for incidence of plant disease
and tendency to volunteer
One Round Bale of switchgrass mulch
thickly covered more than
3 double-row beds, 100 feet long
Rolling out switchgrass mulch before
transplanting took much less time than
following with small square bales
Transplanting into large rolled
switchgrass mulch by hand
Resources
• Native Species Seed - Applied
Ecological Services / Taylor Creek
Restorations, Brodhead, Wis.
• Organic Small Grains - Albert Lea Seed
Co., Albert Lea, Minn.
• Using Hay for Mulch - Organic
Vegetable Seed Trials, UW Madison
• Testing Biodegradable Mulches - ARS
National Center for Agricultural
Utilization Research, Peoria, Ill.