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Alley cropping allows a
producer to grow two complementary crops – an annual crop
like hay amid extremely profitable hardwoods like walnut.
– Photo courtesy of the National Agroforestry Center |
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Agroforestry integrates trees and shrubs with crop or livestock operations
to create more diverse farms, ranches and communities. Research and field demonstrations
of a wide range of practices from around the country prove that trees and shrubs
provide numerous economic and environmental benefits.
Those benefits have not been lost on farmers and ranchers, who
are employing agroforestry strategies in increasing numbers, said
Greg Ruark, director of USDA’s National
Agroforestry Center (NAC) in Lincoln, Neb.
“Small producers can readily integrate many agroforestry practices into
their existing operations and realize an economic benefit, both in terms of
added income and reduced operating costs,” he said.
Alley Cropping
Planting trees and row crops side by side in strips, or alleys, offers great
profit potential. By growing cash crops simultaneously with a long-term tree
crop, farmers can earn annual income while the trees mature. Hardwoods like
walnut, oak, ash and pecan produce high-value logs for lumber or veneer.
While configuration can vary greatly, trees usually are planted in single
rows, widely spaced. The spaces allow room for the annual crops as well as easy
access for farm machinery. You can grow hay, wheat, soybeans and corn, as well
as many vegetables and such specialty crops as St. John’s Wort, a popular
medicinal herb. Consider planting a ground cover, such as a grass-legume mix,
under the tree rows in a strip extending to the width of the tree crowns.
When the trees are small, the annual row crops occupy most of the field and
provide virtually all ofthe income. Most nut crops begin to generate income
within five to 10 years. As the trees grow larger and the level of shade increases,
some producers plant specialty crops that require partial shade, like ginseng
or goldenrod, for an added return.
Alley-cropping systems that match the light, water and nutrient requirements
of both the tree and the agricultural crops lower economic risks by diversifying
farm income while providing erosion control, wildlife habitat and a diversity
of niches for beneficial insects.
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By reducing evaporation,
windbreaks can improve yields.
– Photo courtesy of the National Agroforestry Center |
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Windbreaks
The use of tree strips to control wind erosion has been promoted in the United
States since the “dust-bowl” era of the 1930s. Many of the early
windbreaks have since been cut down or have lost their effectiveness due to
age.
Research has shown, however, that windbreaks provide agricultural benefits
that go beyond erosion control. On a per-field basis, crop yield is almost always
greater because windbreaks reduce crop transpiration and field evaporation losses.
Livestock operators can use windbreaks to provide shelter for animals. Thanks
to several rows of windbreaks, a North Dakota producer maintained all of his
cows during a late-winter blizzard that caused other ranchers to lose 40 to
60 percent of their herds.
Tree strips that also include grasses and legumes provide habitat for wildlife,
beneficial insects and pollinating bees. Windbreaks can even help communities
with harsh winters better handle the dangerous impact of winter storms and significantly
reduce home heating costs.
Producers in Washington’s Columbia Basin planted windbreaks to protect
more than 35,000 acres of fruit orchards from wind damage, according to the
NAC. One row of poplar trees planted seven to 10 feet apart provides about 600
feet of protection. Delicate apple trees benefit when fruit- and limb-damaging
winds are reduced in orchards.
Silvopasture
Many pastures include an occasional tree that either grew inadvertently or
is a remnant from earlier land management activity. What sets silvopasture apart
is the purposeful integration of trees and pasture to gain optimum economic
return. A variety of tree arrangements can create effective silvopasture systems,
with animal stocking density dependent on soils, climate, and the selected tree
and pasture plant species.
Recent research demonstrates that many forage grasses grow as well or better
under up to 50 percent shade as they do in an open pasture. Silvopasture systems
use the same acre of land for livestock grazing and growth of high-value timber.
Livestock – from cattle to hogs – benefit from the shade and shelter
trees provide.
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Specialty crops like shiitake
mushrooms (grown in the forest understory, fetch optimal prices
while helping maintain a natural forest environment.
– Photo courtesy of the National Agroforestry Center |
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Forest farming
Cultivating high-value specialty crops under a forest canopy that has been
modified to provide the appropriate amount of light and micro-climatic
conditions can bring very good returns. Called forest farming, this
practice maintains the forest’s ability to stabilize soil,
provide wildlife habitat, and cycle water and nutrients while modifying
the forest understory. Growers adjust the amount of light allocated
to the understory by thinning, pruning or adding trees. Consider
growing ginseng, shiitake mushrooms and decorative ferns for medicinal,
culinary or ornamental uses in a number of markets, including directly
to consumers. Field borders
Field and roadside borders are an often-overlooked area to add plant diversity
from mixed stands of native perennial plants. They provide habitat for beneficial
insects and birds that prey on insect pests. The borders also help prevent wind
and water erosion and help stop snowdrift. Perennial borders do not require
mowing and – once established – easily outcompete annual weeds.
Native perennials also add to the appearance of the landscape. Local NRCS offices
can recommend an appropriate mix of plants for your area as well as establishment
methods.
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