Gauging Farmers' Water and Pesticide Use
By Don Comis
December 18, 2007
Clark at the Agricultural Research Service (ARS)
Technology Research Unit, Wooster, Ohio, have developed an easy-to-use and
easy- to-build portable instrument so that farmers and greenhouse growers can
test the accuracy of their pressure gauges.
Farmers rely on the accuracy of pressure gauges to ensure that desired rates
of pesticide sprays or irrigation water are applied. But the pressure gauges on
pesticide spraying equipment or irrigation lines often fail after a few years.
So Zhu, an agricultural engineer, and Clark, an engineering technician,
developed a tester that can be assembled by any do-it-yourselfer. The main body
of the tester is commercially available. Farmers go to the field with this
hand-held tester, remove a pressure gauge from their equipment and screw it
into a threaded port on the left hand side of the instrument. On the right hand
side there is an accurate factory-calibrated gauge. In the middle is a small
canister of water attached to a pistol-grip handle.
Squeezing the handle generates pressures to the two gauges for comparison.
If the farmers' gauges don't match the factory-calibrated gauge, farmers have
two choices. If the gauges aren't off by much farmers can keep using their
gauges, but mark the actual location where the dials should be for their
desired readings. But if the gauges are too far off or farmers want to use a
number of different pressure settings, they would buy new gauges.
Extension personnel are already using a tester based on Zhu and Clark's
design. They find the tester a very useful and inexpensive tool for checking
the accuracy of farmers' pressure gauges. This saves farmers money, saves
precious water, and helps keep unneeded pesticides out of the environment.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.