|
Crop
Production
NORTH CENTRAL REGION
 |
 |
|
Planting crops into 4 to
8-inch ridges helps farmers reduce the amount of herbicides
they spray to control weeds.
Photo by T.L. Gettings/Rodale Institute. |
 |
In the mid-1980s, producers seeking ways to conserve soil without sacrificing
yields or profits began to look at ridge tillage. Some farmers wanted to combat
erosion. Others desired an alternative to reduce the fuel and machinery maintenance
expenses associated with the several tractor passes required for conventional
tillage.
First developed in the 1950s, ridge tillage features minimum soil disturbance.
Farmers plant their crops into four- to eight-inch ridges, and the soil remains
undisturbed from harvest to the next planting. During the production season,
ridge-till farmers control weeds with cultivation and minimal use of herbicides.
Ridge-till proponents tout its environmental and profitability advantages over
conventional tillage, which requires three to five tractor passes to prepare
the seedbed--compared to ridge till's one or two. Ridge till also goes hand-in-hand
with "banding" herbicides for weed control, offering farmers the opportunity
to dramatically decrease chemical application by concentrating spraying on the
ridges rather than on the entire field.
While interest was high, producers lacked the real-farm management information
they needed to abandon traditional tillage systems. They worried the conservation
tillage technique would not provide as good a seed-bed as deep tillage had.
"As sustainable agriculture gathered momentum, people began to combine practices
and technologies in new ways in the search for sustainable cropping systems,"
says Rick Exner, who in 1992 received a SARE grant to conduct on-farm research
and demonstration of ridge tillage. "We had pieces before that, but we didn't
really have systems."
Over four years, 29 farmers working in tandem with university researchers conducted
more than 140 replicated on-farm trials involving ridge tillage and ways it
could be incorporated into working production systems. Their research provided
an information base and demonstration sites for farmers and researchers, becoming
a much-needed focal point from which producers could learn how to adapt ridge
tillage to specific, on-farm situations.
Unlike many traditional models where university scientists conduct research
at experiment farms under controlled conditions, the project's trials were designed
and conducted by farmers, many of them affiliated with Practical Farmers of
Iowa (PFI).
PFI, a nonprofit, farmer organization, encourages on-farm research of profitable,
environmentally sound agricultural practices. Many of its members raise corn
and soybeans that, in the past, required extensive tillage. Researching and
demonstrating ridge tillage was a good fit for many of the farmers, who wanted
to investigate how to grow such crops with ridge tillage and realize its potential
benefits. Specifically, they wanted to learn about various methods of fertilizer
placement, cover crops and other factors that would help make their systems
more environmentally sound without giving up profits.
"A lot of sustainable agriculture is management critical," Exner says. "If
you want to find the potential of a system, you have to go where the practitioners
have the management skills to make it work."
The SARE grant helped provide the farmers the opportunity to develop ridge
tillage-related practices, measuring their success through replicated field
comparisons. The ridge-till trials also attracted several ISU scientists, who
extended those studies through their own research. When Exner and the farmer-researchers
examined the results of four years of research, they found:
Ridge till compares very favorably with other tillage systems for yields while
lowering cost of production. While more management-intensive than other systems,
it proved to be very profitable on a per-acre basis.
Ridge till is compatible with frugal use of herbicides, including eliminating
it altogether, reducing rates through banding and alternative measures such
as rotary hoeing, cover cropping and cultivation.
Ridge till offers more weed management flexibility than no-till, letting producers
integrate more sustainable practices and limiting the need for "rescue" herbicide
treatments.
Even though spring release of soil nutrients is delayed in ridge till, the
practice is compatible with the pre-sidedress soil nitrate test used for corn
in Iowa and some other states.
Information learned through the PFI and SARE on-farm ridge tillage research
continues to contribute to the development of more sustainable systems. Today
in Iowa, ridge tillage has gained favor by those sustainable farmers producing
organic and herbicide-free soybeans, which garner premium prices $3 to $10 higher
than regular soybeans in the world market.
"Individually, we've all satisfied some of our goals and doubts by what we've
looked at and learned," says Ray Stonecypher of Floyd, Iowa, one of the farmer
participants.
Stonecypher studied ridge tillage with and without herbicide, with different
nitrogen rates, with dry and liquid fertilizer and with different equipment
modifications, and learned he could reduce his herbicide and fertilizer use
while maintaining yields.
One of the best aspects of the project was developing solutions in concert
with university researchers, says Richard Thompson, who examined potassium uptake
and how the use of ridge tillage facilitated more sustainable rotations as part
of the project. Thompson of Boone, Iowa, remains a national leader in ridge
tillage and on-farm research.
Perhaps most important, the project allowed producers to establish communication
ties with other farmers around the state interested in trying ridge tillage
innovations, lessening the pressure associated with "being different" in the
local farming community.
By its very design, ridge tillage makes on-farm research more inviting to farmers,
Exner says, because the ridges facilitate row identification and marking and
make it easier to track treatment areas from one year to the next.
Ridge till also offers farmers an opportunity to test and incorporate such
practices as intercropping and deep placement of fertilizer. Placing fertilizer
three to five inches below the top of the ridge allows for reduced fertilizer
use and fall application, while still providing all the benefits of traditional
fertilizer application. -- Lisa Jasa
NORTHEAST
REGION
|
 |
|
Used properly, this row-crop
cultivator can replace all or most herbicides sprayed to reduce
weeds.
Photo courtesy of Northeast Region SARE. |
|
Before the advent of herbicides, row crop farmers cultivated their fields with
various mechanical devices to kill yield-reducing weeds. When agrichemical use
intensified in the 1950s, farmers abandoned their hoes and tines to take advantage
of a solution that promised total weed control with a pass or two of an herbicide-spraying
tractor.
Decades later, producers learned chemical weed controls had the potential to
degrade streams and rivers or seep into the groundwater. Today, the pendulum
has begun to swing back in some regions as crop producers seek viable alternatives
to expensive herbicides.
"Farmers are feeling pressure from their neighbors about the amount of spraying
they do, and they have economic concerns as well," says Jane Mt. Pleasant, a
Cornell University researcher who led a SARE project testing mechanical alternatives
to herbicides. "Many farmers think it's better for the land -- they feel stewardship
toward their land and think we need to be acting more carefully. Cultivation
seems to be one way of doing that."
The project explored ways to eliminate herbicides as well as ways to reduce
herbicide use without affecting crop yields. Over five growing seasons, Mt.
Pleasant and colleagues Charles Mohler, Robert Burt and graduate student James
Frisch tested mechanical weed control strategies on field corn at Cornell research
stations and at three New York farms.
Their primary finding: Farmers can completely control weeds using cultivation,
although combining cultivation with a small amount of herbicides may be a better
way to manage time and maintain yields with the least risk.
The researchers found differences of less than $5 an acre when they compared
the production costs of broadcasting herbicides against cultivating. When they
focused on net returns from corn yields, which can be affected if untreated
or uncultivated weeds crowd out the corn, they found integrating chemical and
mechanical weed control posed the least economic risk for growers. Those trying
cultivation exclusively could see yield reductions of 5 percent to 10 percent.
Cultivating requires additional passes across the field. Most conventional
corn growers currently make only one or two passes for weed control. Switching
to mechanical cultivation could require as many as four or five tractor passes,
time and expense few farmers can afford. Combining herbicide banding -- which
applies chemicals in narrow "bands" over crop rows -- with cultivating often
is the best option for most farmers, Mt. Pleasant found.
Organic farmers who use no synthetic chemicals can pass on their additional
costs by charging a premium for their corn. Kathie Arnold, who grows 55 acres
of corn for organic grain to feed to her dairy herd in Truxton, N.Y., replaced
herbicides with cultivation in the 1997 season.
Her reasoning was partly economic; she receives about $19 per hundred weight
for organic milk compared to about $11 for conventional. But Arnold also describes
her "conservation ethic," harboring concerns about the runoff from her farm,
located in the Cheapeake Bay watershed via the Tioughnioga and Susquehanna rivers.
"We'd done some cultivating and banding in the past, but this year, we decided
to transition the whole farm to organic production," she says. "The corn looked
as good as any we've seen, although I spent a lot of time on a tractor this
summer, cultivating."
Arnold took two extra tillage passes before planting to remove any weeds already
present in the soil, then cultivated between the corn rows once or twice during
the growing season.
For other producers, it may make most sense to reduce herbicide use -- up to
65 percent, Mt. Pleasant says, without a reduction in yields -- by incorporating
mechanical cultivation into the crop rotation.
"The audience we want to target are conventional growers who are relying on
chemical control and find ways for them to substantially reduce use of herbicides
without substantially changing their management, their equipment or their yields,"
Mt. Pleasant says. The system "requires some change, but it's a much easier
sell than asking all farmers to throw out all their herbicide sprayers and rely
totally on cultivation."
The project also examined different cultivation tools for corn growers, from
rotary hoes to tine weeders to row crop cultivators. While different mechanical
tools work best in particular settings, Mt. Pleasant stressed that cultivating
devices available today are a far cry from weeders of old.
"These are not the same tools farmers' parents used," she says. "There is a
large array of choices and the tools are much improved."
Farmers who want to cultivate exclusively will want to include tine or rotary
hoes as well as standard row-crop cultivators. Other farmers might benefit most
from cultivators. The type to buy -- rolling versus no-till or S tine -- is
site-specific.
Tillage remains a key component in weed control. A farmer wishing to cultivate
to control weeds will till, plant, then cultivate. If he or she has minimally
tilled the field to help control erosion, it will be harder for some cultivating
tools to penetrate the plant residue left on the surface. Standard cultivators
are out; instead, farmers need to invest in a high-residue cultivator.
One of Mt. Pleasant's more surprising results came when she experimented with
cultivation timing. Conventional wisdom suggests that farmers control weeds
at a specific time in the plant's life cycle, but Mt. Pleasant found more flexibility
without sacrificing weed control and, ultimately, crop yields. Modern field
corn varieties, leafy and vigorous, act as effective competitors for soil nutrients,
sunlight and water against weeds.
"If you let the weeds go, they will substantially reduce yields," she says.
"But the idea that they have to be controlled in a certain small
window is false. It's much wider than we had thought." -- Valerie
Berton
SOUTHERN REGION
|
 |
|
Lupin, a protein-rich forage
and cover crop, helps increase tropical corn silage yields,
generating interest from farmers across the South. Photo courtesy
of Auburn University. |
|
In the early 1940s, lupins were grown extensively across the South as a nitrogen-fixing
cover crop for cotton. In its heyday, lupins spread across 2.5 million southern
acres.
Today, the legume is rarely used by farmers. When chemical fertilizers gained
popularity following World War II, lupins lost their niche as a cover crop.
The consuming public, too, has turned away from a nutty, nutritious foodstuff
similar to lentils.
Don't write off lupins so fast, says USDA Agricultural Research Service (ARS)
soil researcher Wayne Reeves, who came across old literature on the legume while
searching for alternative crops to incorporate into sustainable cropping systems
in the South. In what he touts as a viable alternative to its widely planted
cousin -- soybeans -- lupins hold great potential both as an animal forage and
as a product for human consumption.
The write-up piqued his interest in further studying lupins in rotation with
common commodities like wheat and soybeans, as well as alternatives such as
pearl millet and tropical corn. Reeves, with help from collaborators, obtained
a SARE grant in 1993 to test the viability, profitability and resource-conserving
potential of lupins in combination with other field crops.
Lupins, pearl millet and tropical corn embellish traditional crop rotations
by extending the growing season. Lupins can over-winter while tropical corn
and pearl millet can be planted in late spring/early summer for a late harvest.
"Lupin provides an option to grow a feed grain in winter," Reeves says. It
shares the high protein content of soybeans, but is easier to process. "A farmer
can crush lupins on site without having to buy back a processed feed like soybean
meal. You just grind it to crack the hard shell, mix with feed, and you have
a good high-protein feed source to use on farm."
As a legume, lupins help fix nitrogen, a real plus in the South, which faces
more fertility challenges than other regions. Its wet, warm winters cause denitrification,
and its sandy soils facilitate nitrogen leaching.
Working with researchers at Auburn University, the University of Florida and
USDA-ARS researchers in Georgia and at the National Soil Dynamics Lab in Auburn,
Ala., Reeves tested six cropping systems that included lupins, tropical corn
and pearl millet. Reeves was most impressed by the lupins' ability to fix nitrogen.
At one location, lupin acted as an efficient "green manure" that resulted in
tropical corn silage yields of 20.5 tons an acre. Those results have generated
interest from cotton growers in the Florida panhandle, southern Georgia, Alabama,
North Carolina and South Carolina. Growers want to take advantage of a cheap,
efficient way of adding nitrogen without setting the stage for water contamination
problems that can occur with excessive use of purchased fertilizer.
Lupin's potential as an animal feed or forage and for human food was limited
in his experiment by plant genetics, Reeves says. The lupin variety the researchers
used proved too sensitive to fungal diseases when planted in spring and summer.
The optimum variety would mature earlier -- in May -- to allow another crop,
such as tropical corn, to follow during the summer growing season.
The researchers plan to follow up the "intense interest" in using lupin as
a cover crop by encouraging seed companies to stock and market two varieties
that show most promise. They also are producing a lupin video and management
guide.
Tropical corn provides an opportunity to follow lupin in late spring, unlike
standard field corn, which southern growers plant in April to reduce the potential
for insect damage that can occur when the crop is planted too late. Tropical
corn, bred in tropical climes, exhibits a tolerance to common southern pests
like armyworm, says David Wright, Extension specialist for agronomy at the University
of Florida and a cooperator on the SARE project.
Those findings alone could have a significant impact on southern growers, who
could work tropical corn into wheat and soybean rotations. Indeed, the total
acreage of tropical corn went from about 3,000 acres 10 years ago to close to
100,000 today, partly a "direct result of the work we have done on tropical
corn," Wright says.
Not only did tropical corn yields benefit from following lupin, but pearl millet
also performed well behind the legume. At one location, millet yields equalled
129 bushels per acre, with lupin supplying about the equivalent of 60 pounds
of applied nitrogen. Millet holds perhaps the most potential as a successful
forage alternative in the South because of its drought-tolerance.
Pearl millet is a high-protein grain, measuring between 12 and 14 percent compared
to corn's 9 to 10 percent. Pearl millet, therefore, makes a nutritious feed
grain for livestock, par-ticularly poultry, appealing to producers across the
country who have called Georgia Experiment Station researcher Wayne Hanna for
information.
Hanna advocates pearl millet for southern rotations because it survives heat
and drought stress. He speculates the grain adapted to such conditions because
of its likely origin in tropical Africa."
We have to ship grain in from the Corn Belt," Hanna says. "Our idea was to
come up with an alternative crop that likes the droughty, acid soils of the
South, and pearl millet fits the bill."
Its ability to withstand African-style heat means pearl millet can grow in
late summer. It can be planted as late as mid-July, seemingly thriving in hot,
dry periods.
"This crop can be planted after you harvest wheat or canola at the end of May
and June, when you can't come in with any other grain crop," Hanna says. "It's
not sensitive to the day length and has a short maturing season." -- Valerie
Berton
WESTERN REGION
|
 |
|
Workers at the UC-Davis
agronomy farm harvest tomatoes by hand to verify yields in the
SAFS project.
Photo by Jack Kelly Clark. |
|
Both supporters and skeptics in California's Sacramento Valley wondered how sustainable
agriculture farming systems would fare compared to conventional in the first large-scale,
head-to-head competition of its kind in the nation's most productive agricultural
state.
A decade later, people are still intrigued by the comprehensive SARE-funded
research project, but what farmers really want to know is how they can incorporate
some of the profitable, environmentally friendly techniques identified in the
UC-Davis study.
"Now we don't ask whether low-input and organic production is viable," says
Bruce Rominger, a Yolo County farmer who raises vegetables and field crops and
acts as an adviser for the project. "We know it's viable. We're just trying
to perfect it."
Information gleaned from the long-term Sustainable Agriculture Farming Systems
(SAFS) project--from feeding soil with cover crops to growing more corn with
fewer pesticides and synthetic fertilizers--could help producers like Rominger
make a transition to alternative production techniques.
While typical agricultural research studies last two to three years, the SAFS
project, now celebrating its 10th anniversary, will run for 12 years. The research
compares conventional, low-input and organic cropping systems for tomatoes,
corn, safflowers and beans based on pest populations, soil health, crop yields
and economic viability.
Researchers are encouraged by the economic potential of crops grown with reduced
chemical inputs. Low-input corn, grown with half the conventional amount of
pesticides and much less synthetic fertilizer, consistently ranked first in
both yields and profits.
In a 1997 comparison, price premiums for organic crops pushed their net returns
to $292 per acre, just under the top-ranking, two-year conventional rotation's
returns of $305 per acre. Aside from profits, researchers worry that long-term
conventional production has the potential to increase disease and degrade soil.
Along with researchers ranging from agricultural economists to water scientists,
farmers and Extension specialists are involved in every step of the project.
"After all, farmers have always been our foremost experimenters," says Steve
Temple, the crop production researcher who leads the project.
The project combines rigorous research with real-world management. The rigor
can be found in the 56 carefully managed, one-third-acre plots on the university's
agronomy farm. As for the realism, all systems are managed to make a profit,
using best farmer practices.
Researchers are studying four different production systems, comparing a two-year
conventional rotation of processing tomatoes and wheat to four-year rotations
of tomatoes, safflower, beans and corn grown using conventional, low-input and
organic practices.
Conventional management follows typical farming practices in the Sacramento
Valley, using synthetic fertilizers and pesticides. Low-input management includes
cover crops and supplemental mineral fertilizers, as well as pesticides, when
warranted. Organic rotations are free of synthetic chemicals and meet state
organic certification standards.
Researchers have wrestled with problems common in making a transition from
conventional to alternative practices.
To find solutions, researchers get creative at an eight-acre area adjacent
to the test plots, nicknamed the "playground," where they test new management
ideas before incorporating them into the 56 long-term research plots. Some of
the ideas--such as mounting a propane flamer on the tractor for weed control
or using weed-eating geese to cut the costs of hand-hoeing--are admittedly offbeat.
But the brainstorming has provided some serious improvements in the research.
For example, in the cold spring weather, cover crops and composted manure don't
always break down early enough in the season to supply crops with nitrogen,
reducing yields.
One solution to nitrogen deficiency was to irrigate fast-growing grass and
grass/ legume cover crop mixtures in the fall to build nitrogen early enough
to help crops in the spring. Another playground idea that bore fruit was using
tomato transplants instead of seeding in low-input and organic systems. Transplanting
gave cover crops longer to grow and increased yields. Direct-seeded tomatoes
should be planted about Feb. 15, while transplants can be planted as late as
April 10, allowing time for the cover crop to accumulate more biomass and fix
nitrogen.
To help farmers compare the bottom line for each rotation, economists use actual
input costs, crop yields and market prices to model returns for hypothetical
2,000-acre farms.
Except for weeds, which accounted for 25 percent of operating costs, significant
pest problems did not emerge with alternative management. But the high labor
costs for hand hoeing tomatoes considerably raised the costs of growing low-input
and organic systems.
Overall, the four-year rotations have shown comparable returns over the years,
though each has strengths and weaknesses. Because processing tomatoes are the
most profitable crop, a two-year conventional tomato/wheat rotation won out
economically, though the production system raised concerns about the potential
for increased disease and soil degradation. A conventional four-year rotation
has the lowest costs, but not the highest returns. Reduced pesticide use in
the alternative rotations lowered input costs and the risk of groundwater contamination.
Alternative methods also improve soil structure, along with its ability to take
in water and nutrients.
Low-input systems, on the other hand, produce well but have higher costs than
conventional. Organic production, the most expensive, also showed the best profits
in 1997, if current price premiums were factored in.
Rominger, who uses both conventional and organic methods on his farm, says
the project's results can be applied in the real world. It's helped him learn
"volumes" about soil science and given him the idea of using transplants with
organic tomatoes.
"We can take risks that farmers can't," says Sean Clark, the research manager.
"We want to be a proving ground for what works." -- D'Lyn Ford
Ten Years
of SARE Home
 Top
|
