harvesting operations with heavy equipment will succeed
A tillage program does not need to be rigid. Fields that
only if traffic can be restricted to dry conditions or fixed
are zone-, strip-, or no-tilled may occasionally need a
lanes within the field. Even zone-tillage methods will work
full-field tillage pass to provide compaction relief or to
better if fixed lanes are used for heavy harvest equipment.
incorporate amendments like lime. But this should be
done on a very limited basis. Although a flexible tillage
SUMMARY
program offers a number of benefits, aggressive tillage
Reducing the intensity of tillage can help improve the
with a moldboard plow and harrows can readily destroy
soil in many ways. Maintaining more residue on the sur-
the favorable soil structure built up by years of no-till
face reduces runoff and erosion, while the reduction in
management.
soil disturbance allows for earthworm holes and old root
channels to rapidly conduct water from intense rain-
Timing of Field Operations
storms into the soil. There are many choices of reduced
The success of a tillage system depends on many factors.
tillage systems, and equipment is available to help farm-
For example, reduced tillage systems, especially in the
ers succeed. Using cover crops along with reduced tillage
early transition years, may require more attention to
has been found to be a winning combination, providing
nitrogen management (often higher rates are needed
surface cover rapidly and helping to control weeds.
initially, lower rates eventually), as well as weed, insect,
and disease control. Also, the performance of tillage
SOURcES
Cornell Recommendations for Integrated Field Crop Production.
systems may be affected by the timing of field opera-
2000. Ithaca, NY: Cornell Cooperative Extension.
tions. If tillage or planting is done when the soil is too
Manuring. 1979. Cooperative Extension Service Publication AY-
wet (when its water content is above the plastic limit),
222. West Lafayette, IN: Purdue University.
cloddiness and poor seed placement may result in poor
Moebius, B.N., H.M. van Es, J.O. Idowu, R.R. Schindelbeck, D.J.
Clune, D.W. Wolfe, G.S. Abawi, J.E. Thies, B.K. Gugino, and R.
stands. Also, a zone building operation done in plastic
Lucey. 2008. Long-term removal of maize residue for bioenergy:
soil results in smeared surfaces and an open slot that
Will it affect soil quality? Soil Science Society of America Jour-
nal 72: 960–969.
does not allow for good seed-soil contact. A “ball test”
Ontario Ministry of Agriculture, Food, and Rural Affairs. 1997. No-
(chapter 6) helps ensure that field conditions are right
till: Making it Work. Available from the Ontario Federation of
and is especially important when performing deeper till-
Agriculture, Toronto, Ontario, Canada.
age. Tillage is also not recommended when the soil is too
Rodale Institute. No-Till Revolution. http://rodaleinstitute.org/
no-till_revolution.
dry, because it may be too hard, clods may be very large,
Tull, J. 1733. The Horse-Hoeing Husbandry: Or an Essay on the
and excess dust may be created, especially on compacted
Principles of Tillage and Vegetation. Printed by A. Rhames,
soils. Ideal tillage conditions generally occur when soils
for R. Gunne, G. Risk, G. Ewing, W. Smith, & Smith and Bruce,
Booksellers. Available online through Core Historical Literature
are at field-capacity water content (after a few days of
of Agriculture, Albert R. Mann Library, Cornell University.
free drainage and evaporation), except for fine-textured
http://chla.library.cornell.edu.
clays, which need more drying (see chapter 15).
van Es, H.M., A.T. DeGaetano, and D.S. Wilks. 1998. Upscaling
plot-based research information: Frost tillage. Nutrient Cycling
Because soil compaction may affect the success of
in Agroecosystems 50: 85–90.
reduced tillage, a whole-system approach to soil manage-
ment is needed. For example, no-till systems that involve
184
Building SoilS for Better CropS: SuStainaBle Soil ManageMent
a case study
steve groFF
lanCaster County, Pennsylvania
Steve Groff raises vegetables, grains, and cover crop
He pioneered what he likes to call the “Permanent
seeds on his 215-acre farm in Lancaster County,
Cover” cropping system when the Pennsylvania chapter
Pennsylvania, but his soil shows none of the degrada-
of the Soil and Water Conservation Society bought a
tion that can occur with intensive cropping. Mixing cash
no-till transplanter that could plant vegetable seedlings
crops such as corn, alfalfa, soybeans, and tomatoes with
into slots cut into cover crop residue. Groff was one of
cover crops in a unique no-till system, Groff has kept
the first farmers to try it. The slots are just big enough
portions of his farm untouched by a plow for more than
for the young plants and do not disturb the soil on
two decades.
either side. The result: Groff can prolong the erosion-
“No-till is a practical answer to concerns about ero-
slowing benefits of cover crops. He now owns two no-till
sion, soil quality, and soil health,” says Groff, who won a
national no-till award in 1999. “I want to leave the soil in
Groff stresses, however, that switching to
better condition than I found it.”
Groff confronted a rolling landscape pocked by gul-
no-till alone isn’t enough. He has created a new
lies when he began farming with his father after gradu-
system, reliant on cover crops, rotations, and
ating from high school. They regularly used herbicides
no-till, to improve the soil. He’s convinced such
and insecticides, tilled annually or semiannually, and
methods contribute to better yields of healthy
rarely used cover crops. Like other farmers in Lancaster
crops, especially during weather extremes.
County, they ignored the effects of tillage on a sloped
landscape, which causes an average of 9 tons of soil per
acre to wash into the Chesapeake Bay every year.
Tired of watching 2-foot-deep crevices form on the
planters—one for planting tomatoes, the other for corn
hillsides after every heavy rain, Groff began experiment-
and pumpkins—customized with parts and implements
ing with no-till to protect and improve the soil. “We used
from several different equipment companies.
to have to fill in ditches to get machinery in to harvest,”
Groff’s no-till system relies on a selection of cover
Groff says. “I didn’t think that was right.”
crops and residues that blanket the soil virtually all year.
Groff stresses, however, that switching to no-till alone
“The amount of acreage I devote to different cover crops
isn’t enough. He has created a new system, reliant on
every year is really subjective,” he says, noting that he
cover crops, rotations, and no-till, to improve the soil.
constantly modifies his cropping plans based on field
He’s convinced such methods contribute to better yields
observations, weather conditions, timing considerations,
of healthy crops, especially during weather extremes.
and other factors. In the fall, he uses a no-till seeder to
185
building soils For better CroPs: sustainable soil ManageMent
drill a combination of rye and hairy vetch (at seeding
mulch. Once it’s flat, he makes a pass with the no-till
rates of 30 and 25 pounds per acre, respectively). He
planter or transplanter.
likes the pairing because their root structures grow in
The system creates a very real side benefit in
different patterns, and the vegetation left behind after
reduced insect pest pressure. Once an annual problem,
killing leaves different residues on the soil surface.
Colorado potato beetle damage has all but disappeared
Introduced to forage radish through University of
from Groff’s tomatoes. Since he began planting into the
Maryland cover crop research trials hosted at his farm,
mulch, he has greatly reduced the spraying of pesticides.
Groff was so impressed by what he saw that he decided
The thick mat also prevents splashing of soil during rain,
to integrate it into his cover crop combinations. His typi-
a primary cause of early blight on tomatoes. “We have
cal rotations include planting forage radish and oats or
slashed our pesticide and fertilizer bill nearly in half,
forage radish and crimson clover mixtures before sweet
compared to a conventional tillage system,” Groff says.
corn, and a forage radish–rye–vetch mixture before
“At the same time, we’re building valuable topsoil and
pumpkins.
not sacrificing yields.”
Several attributes make forage radish a practical
“No-till is not a miracle, but it works for me,” he
choice for no-till farmers. For example, its taproots can
says. “It’s good for my bottom line, I’m saving soil,
alleviate compaction problems—so much so that Groff
and I’m reducing pesticides and increasing profits.”
now prefers using radishes instead of his deep ripper to
He emphasizes that benefits from no-till management
loosen soil in his driveways. Complete dieback following
have developed gradually, along with his experience in
hard frost, impressive weed suppression into spring, and
handling each field. Knowing when to stay off wet fields
relatively rapid nutrient cycling add to forage radish’s
and choosing the right crop and cover crop rotations,
appeal.
he says, can help farmers new to no-till avoid poten-
Upon discovering a few years ago that forage radish
tial compaction and fertility problems. “My soils have
cover crop seed was not available locally, Groff decided
developed a stability that lets me get away with things
to grow his own and sell the surplus to other farmers. He
that I couldn’t do earlier,” he says. “You earn the right to
has increased his seed production every year in response
be out there as your soil gets more stable. Basically, the
to the “substantial growing interest” of conventional
rules of the game change as the game is played.”
farmers in cover cropping. He now fills seed orders from
Groff is convinced his crops are better than those
farmers across the U.S.
produced in soils managed conventionally, especially
In the spring, Groff uses a rolling stalk-chopper—
during weather extremes. His soils foster high levels of
modified from Midwest machines that chop cornstalks
earthworm and other biological activity deep in the soil.
after harvest—to kill overwintering covers. He typically
He promotes his system at annual summer field days
sprays glyphosate at low levels (1/2 pint, or $1 per acre)
that draw huge crowds of farmers and through his infor-
before rolling to ensure a more complete kill. The chop-
mative website, www.cedarmeadowfarm.com.
per flattens and crimps the cover crop, providing a thick
—uPdated by aMy kreMen
186
building soils For better CroPs: sustainable soil ManageMent
