1945 Windbreaks: Natural Erosion Control - webapps8

panding irrigation areas, have suffered
soil losses because of windbreak removal.
Benton County commissioners
have passed an ordinance controlling
removal of windbreaks, one of the few
such laws in the nation. It requires
farmers to develop alternative plans
for soil conservation before they can
remove a field windbreak. Kevin Adelman,
SCS technician for the two
counties, said the ordinance has cut
windbreak removal in half.
About 30 miles of windbreaks have
been removed in Benton and Sherburne
counties, mainly because of new
irrigation projects. But only two miles
have been replaced. William Held of
Rice has started to replace some of the
six miles of shelterbelt he removed,
planting trees on the perimeter of his
fields. (Windbreaks on the outside of a
field do not offer the protection of
single-row windbreaks every 600 feet.
However, SCS endorses their use in
combination with other soil conservation
methods.)
"Most farmers in the two counties
have begun a program of minimum
tillage or mulch tillage in an effort to
protect the soil," said Adelman. One
landowner, Joe Gottward of Rice,
moved part of his windbreak out of
the way of his center pivot system and
replanted the trees elsewhere. Other
farmers have attempted to replant, but
dry weather in 1975 and 1976 killed
the young trees. Farmers indicate that,
if they receive enough snow this winter,
they will try again next spring.
Many soil experts believe that windbreaks
not only will prevent wind
erosion on an irrigated field, but will
make the unit more efficient. Water
can be distributed better with less
evaporation if a windbreak adjoins the
pivot system.
Irrigation isn't the only cause of
windbreak removal. In the Red River
Valley, windbreaks of Siberian elm
planted about 15 years ago are now
dying. "The fungus has been isolated,
but it is a secondary cause of death,"
said Scottie Scholten, University of
Minnesota College of Forestry professor.
"The trees have been weakened
by annual crop spraying."
John Hultgren, SCS Woodland Conservationist
in Minnesota, agrees that
crop spray may damage windbreaks of
Siberian elm. "Monoculture is always a
problem," he said. "Siberian elm
looked like the perfect tree, so that
was all that was planted. Today we
encourage a variety of trees in a
shelterbelt, such as a mixture of Siberian
elm, green ash, and cottonwood.
This decreases the likelihood of
disease and insect infestation as well as
the chance of crop spray wiping out
the entire shelterbelt."
The SCS, U.S. Forest Service Extension
Service, and the University of
Minnesota Experiment Stations are
constantly searching for new seedstock
and alternative species to use in field
windbreaks. "We are now looking at a
seed source which will give us a ponderosa
pine with more upright
branches for better snow distribution
across the field," said Scholten. "This
)ANUA RY —FEBRUARY 1978 39