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building soils For better CroPs: sustainable soil ManageMent
a case study
bob Muth
glouCester County, neW Jersey
Farming 118 acres in what has recently become a bedroom
a few times through his rotation, in order to keep soil
community of Philadelphia, Bob Muth and his wife,
organic matter within an optimum range of 3.5–5%.
Leda, raise a wide range of vegetables, small fruits, flow-
“Anything higher than that, and I risk nutrient leach-
ers, and hay, which are sold to wholesalers and through
ing,” he notes.
a 325-member CSA (community-supported agriculture).
Muth likes to use drip irrigation to reduce plant
Muth’s operation is based on his passion for soil
stress and disease and improve water use efficiency.
building. Since he took over running the family farm
“Water shortage is my biggest issue on the home farm,
twenty-two years ago, Muth has spread thick layers of
where I’ve got a well that pumps only 20–22 gallons a
leaf mulch, provided for free by his local municipality,
minute,” he says. A residential development boom on
at the home farm, on rented fields, and, eventually, on
the land surrounding his farm in recent years has drasti-
additional purchased tracts of land. Mulching forms
cally reduced the available groundwater. He says, “You
part of a rotation scheme that he devised early on and
have to be creative about breaking up your fields into
to which he has remained faithful: Only a fifth of his
zones in order to make water do what you need it to do.”
tillable acreage is planted in cash crops each year; the
Muth relies on a range of IPM (integrated pest man-
remaining area is put into pasture or cover crops. “When
agement) techniques for pest and disease control. He
I started mulching and using this rotation, my [farmer]
scouts his fields daily and takes notes of his observations
neighbors thought I was losing my marbles,” he says.
throughout each cropping cycle. “It’s worth investing
“The prevalent idea at the time was that you had to farm
in a jeweler’s loop,” he advises, “because it’s the pests
a lot of acreage as intensively as possible.”
that are most difficult to see—like the white flies, spider
Muth’s rotation—a high-value crop the first year, fol-
mites, and thrips—that will get you.” He regularly plants
lowed by a leaf application the second year, two to three
trap-crop borders around his high-value crop fields,
years of a hay and sudex pasture, and ending with a year
which enable him to monitor pest populations and
of a rye-vetch cover crop—really boosts the quality of
determine when and how much to spray. For example,
his sandy soils. “With this strategy, I get all the posi-
he suggests using red kale or mizuna as a trap crop to
tive indicators such as high CEC, organic matter, and
prevent tarnished plant bug damage on savoy cabbage.
nutrient levels, including enough N to grow good-quality
“You have to figure out what [pests] require in their
crops without a lot of inputs,” he says.
life cycles and disrupt them,” he says. After several years
Muth tests the soil in his fields annually and care-
of observation, “you begin to recognize if you’ve got a
fully monitors changes in the data. “I like having hard
crop for which you haven’t figured out a good control
numbers to back up what I’m observing in the field and
strategy.”
to make good decisions as the years go by,” he says.
Muth likes to encourage beneficial insect populations
Such careful attention to detail has led him to reduce
by leaving flowering strips of cover crops unmowed
the thickness of leaf applications once fields have cycled
on the borders of his crop fields. He has found that
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building soils For better CroPs: sustainable soil ManageMent
interplanting cover crops—adding buckwheat and dill
Muth’s decisions to “go with a good soil building
to vetch, for example—significantly extends bloom time,
program” and IPM methods have smoothed his gradual
thus fostering multiple generations of beneficial insects.
transition of acreage into certified organic production.
In high tunnels, where he grows berries and flowers,
“When I started getting into organics, people told me,
he controls aphids and spider mites by releasing preda-
‘Bob, you better be careful or you’re going to end up with
tory mites. He selected a special film to cover the tunnels
buggy stuff that’s full of disease that people don’t want.’
that enhances light diffusion, reduces condensate drip
But I haven’t seen any of that,” he says. “I haven’t been
from the ceiling and purlins, and helps prevent over-
overwhelmed; in general, pests and disease levels on my
heated conditions, ensuring an overall superior growing
farm amount to no more than a minor annoyance.”
environment.
Encouraged by his success and customer demand,
“There are so many things you can do to help
Muth is applying his expertise to figuring out how to
yourself,” he says. He has learned how to prevent
grow more “difficult” crops organically. For example,
early-season pythium rot by waiting to plant crops until
when area specialists said that growing organic super
a preceding rye-vetch cover is fully broken down and
sweet corn in New Jersey would be impossible, he
could not resist the challenge. “We decided to start our
corn plugs in the greenhouse,” he says, noting that “the
As an added bonus, he says that by
people at Rutgers thought this was revolutionary.” He
diffusing more light into the plant canopy,
transplants corn plugs out after ten or eleven days (to
prevent plugs from becoming pot-bound, which reduces
the mulch boosts the color intensity
ear length) onto plastic mulch and keeps row covers over
(and marketability) of his produce.
the plants until they are 12 to 18 inches tall. Such strate-
gies effectively foil corn earworm and corn borers, Muth
the soil warms up. He keeps pythium—which also likes
says. “You can grow corn early, scout it closely, and with
hot and wet conditions—in check later in the season by
spot use of approved sprays for organic production, get
planting crops out on highly reflective metallic plastic
three weeks of absolutely clean, fantastic-quality organic
mulch, under which soil temperatures are lower relative
corn in July.” His customers are thrilled and are willing
to those that occur under other colors of plastic mulch.
to pay him a premium price for the fruits of his discov-
The shiny mulch also repels aphids and thrips, Muth
ery. Muth says he hopes to crack the mystery of how to
notes. As an added bonus, he says that by diffusing more
produce high-quality organic peaches next.
light into the plant canopy, the mulch boosts the color
With so many new techniques emerging, and con-
intensity (and marketability) of his produce.
sumers increasingly interested in buying locally and
Overall, instead of adhering to a strict spray sched-
organically produced food, Muth says this is “an exciting
ule, which “may control one critter but make things
time to be in agriculture.” “If you’re savvy, you can farm
worse if you also kill your beneficials in the process,”
a small piece of land and make a good living.”
Muth suggests “layering together” different types of
“I wish I was twenty-one again,” he says, “because I’d
controls, such as improving soil quality, putting up bat
do it all over again. It’s a pleasure to get out there and
houses, creating insectaries of flowering covers, using
get to work.”
sprays judiciously, and letting pest and disease manage-
—uPdated by aMy kreMen
ment strategies evolve as time goes by.
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building soils For better CroPs: sustainable soil ManageMent
