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A multi-fan spray system is under study by ARS researchers to reduce
aerial drift of pesticide from orchards and nurseries to nearby fields and
neighborhoods. This way, more of the chemical stays where it can
suppress fruit-munching insects, fungal blight and diseases that cause
millions of dollars in orchard crop losses annually. The system can
reduce spray drift by at least 40 percent. It uses fans tilted downward
and upward, rather than the conventional axial-flow system that sprays
chemicals in a large fan-like pattern. The system's downward tilted fan
more precisely aims pesticides at plant parts. The multi-fan system also
is taller than conventional orchard sprayers, for better coverage on the
top side of fruit trees.
Application Technology Research Laboratory,
Wooster, OH
Ross Brazee, (216) 263-3870
On rangeland where no livestock has grazed, one might assume the soil
would be healthier. Not so, according to an ARS study of two
measurements of soil health--organic carbon and nitrogen. Scientists
compared grazed land to range that had been left free of livestock for 40
years. On ungrazed pastures, the scientists found more carbon and
nitrogen were "tied up" in dead plant material that breaks down and blows
away. By contrast, grazed areas retained over 30 percent more carbon and
nitrogen in the top three inches and about 15 percent more in the second
three inches. Below six inches, there was little difference in carbon and
nitrogen between soils under grazing or ungrazed rangeland. Grazing
cattle trample the plant material into small pieces, helping it decompose
and mix into soil. In addition, they add manure which is rich in plant
nutrients. Scientists compared grazing plots on short- and mixed-grass
rangelands that are representative of more than 300 million acres in the
West. This study of soil nutrients was part of continuing efforts to
understand and find ways to improve or sustain valuable grazing lands.
High Plains Grasslands Research Station, Cheyenne, WY
Richard H. Hart, (307) 772-2433
Just how well earthworms can enrich soil quality depends on what they
eat. ARS tests confirmed that the type of crop makes a
difference--earthworms feeding in soybean fields deposit a higher
concentration of nitrogen and protein than those eating in corn fields.
Earthworms (Lumbricus terrestris) take in the nutrients
from munching on crop residues plus microbes feeding on plant parts. The
worms then excrete a substance loaded with carbon, nitrogen and other
nutrients that are more readily used by crops for growth. Another finding
from the soil tests: Reduced tillage means more worms. That's because
less tillage leaves more organic matter for worms to consume.
Soil and
Water Management Research, St. Paul, MN
Dennis Linden, 612-625-6798
Sagebrush seedlings have a better chance at surviving on reclaimed
mining land if seeds are planted according to new guidelines developed by
ARS scientists. The guidelines also will help ensure compliance with
federal and state strip mine laws that require disturbed lands to be
restored to their original condition. This requirement applies to all
native species including shrubs like sagebrush. ARS scientists found that
the key elements for survival of sagebrush seedlings are: (1) store seed
at room temperature and humidify for up to six months before seeding; (2)
reseed using topsoil recently removed from an adjacent mining area; (3)
use the heaviest seed available, and (4) provide mulch. Sagebrush species
and sub-species are the most abundant native shrub in North America,
growing on about 420,000 square miles of rangeland in 11 western states.
The shrubs provide a good source of winter protein for wildlife, and
ranchers value the nutrients that the plants supply to cattle, especially
during winter or extended drought.
High Plains Grasslands Research Station, Cheyenne, WY
D. Terrance Booth/Gerald E. Schuman, (307) 772-2433
Last updated: October 22, 1996
Return to: Quarterly Report
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