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Topsoil Erosion Expensive and Preventable
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Harry's
attempt to recapture soil
eroded from his orchard proved
to be too
little, too late.
Soil erosion has written
significant chapters in the history of American agriculture and society. The
Dust Bowl of the thirties, which affected 25,000 square miles of the nation's
prairie states, comes immediately to mind. The loss of windblown topsoil
exacerbated the economic tragedy of a broken stock market and bank closures
already gripping the country in the Great Depression. Farmers of the era could
not feed even themselves and had to abandon not only the land but a way of life.
Poor farming techniques and insufficient land conservation practices in the
1920's left a legacy of misery.
Erosion will never be completely
stopped, for it is one of nature's most powerful and persistent forces. Without
erosion we'd have no beaches or fertile bottomlands. Yet farmland erosion
continues today as a major concern even though the devastating dust storms of
the past are no longer the prime cause of soil loss because of better
cultivation practices. Economic impact can still be significant when erosion is
water caused. Replacement of agricultural topsoil may be prohibitively
expensive, and depending on the magnitude of loss, may not be possible. Putting
aside all the other reasons to avoid erosion—downstream damage liability,
government regulation, production losses—is the cost of soil itself.
High Cost to Repair
A half inch of topsoil lost from an
acre of land is equal to 67 cubic yards! Replacing that much material
would take about 7 six-cubic yard capacity dumptrucks at an estimated cost of
$27 a yard: over $1,800 for just one acre! And that is before on-site
costs of labor, fuel and amendments needed to prepare the soil for planting. Add
in lost time and multiply by total acreage and the bill becomes staggering.
Vineyards and orchards are often
planted on slopes where it would be difficult or impractical to plant short
duration vegetable crops, such as broccoli or lettuce, that require significant
irrigation. In modern tradition the lanes between trees or grape vines are
disced clean, exposing them to the ravages of water and wind scouring. Yet, even
a 1- or 2-degree slope can promote huge stormwater runoff that takes precious
topsoil away. Plenty of examples of such erosion occurred with last winter's El
Niño storms. The hot, dry summer that followed continued the erosion,
succumbing to thieving winds.
What to DoThe case is clear and strong for
avoidance-avoidance of :
- wind erosion
- water erosion
- soil replacement.
There is a cheap answer, one that is so
simple and natural as to be embarrassingly obvious. Not only does this solution
provide effective erosion prevention, it saves many times its cost in saved
labor, fuel and reduced need for pesticides. On top of that, it is a beautiful
addition to agricultural areas—a particular advantage for vineyard owners
seeking to create an inviting atmosphere for guests and to stimulate sales.Cover crops replace the bare dirt rows
between orchard trees and grape vines. The benefits of cover cropping are
manifold according to University of California Davis scientists, not the least
of which is erosion prevention. This additional vegetation in vineyards and
orchards stabilizes the soil and absorbs much of the rainfall. Runoff is
dramatically reduced and what there is carries a far lower load of precious
topsoil. In dry weather, reduced dust is important for mites make a home in dust
that settles on leaves. Dry soil is protected by the vegetation, reducing wind
erosion.
Another important effect of cover crops
is that they reseed themselves. Mechanically chopping the cover crop in the fall
and leaving it in place is all that is needed to not only distribute seed and
prepare for the next year's crop, but to build up a matrix of plant waste that
provides mulch and a carpet upon which tractors and field equipment can be
driven—what the scientists call improved trafficability. Even in the rain,
tires do not create muddy ruts because the ground is protected.Cover crops provide habitat, nectar and
pollen that will sustain beneficial arthropods when they aren't out battling
crop-destroying pests. |
Albright's Insecta-Flora mix creates a
natural insectary that attracts these beneficials and provides an alternate
target for the harmful insects. There's more. Albright has premixed cover crops
and ground cover mixes and can create site-specific custom blends for orchards
and vineyards in all California bioregions.
Read more about beneficial insects and erosion control and topsoil erosion.
To order Insecta-Flora from Albright Seed Company, call
1-(805) 684-0436.
Choose from more articles from Albright Seed Company. All our products come with an extra ingredient at no extra cost—30 years' experience.
