
Precision Agriculture: Giving Plants Just
What They NeedBy Sean Adams February 5, 1997A new irrigation system in the works
from USDA scientists is based on a very
simple idea: Give each plant precisely the amounts of water and nutrients it
needs. The new system is part of an emerging high-tech science called
precision agriculture. That means providing water and fertilizer to
plants based on their particular needs in small areas, instead treating the
whole field uniformly. Scientists with USDAs Agricultural
Research Service started with a commercial center pivot irrigation system,
which pivots in a giant circle, sprinkling plants underneath. The amount of
water delivered to each plant depends on how quickly the irrigation pipe moves
around the circle. In two years of field tests, the scientists modified the sprinkler system by
dividing its length into several sections. Then they gave each section three
manifolds that allow the water to be sprayed from nozzles at eight different
rates. On a 15-acre field, researchers can precisely apply water and nutrients on
up to 500 separate segments, each about the size of a two-car garage. The
long-term goal: precise irrigation of each part of a field, based on the type
of soil and crop present in that segment. This will help farmers make sure
plants get enough water in sandy areas, while avoiding flooding and runoff in
others with different slopes, clay content or soil compaction. Researchers are working cooperatively with Valmont Industries, Inc., of Valley, Neb., a
large manufacturer of commercial irrigation systems, to further refine the
system. Scientific contact: Carl R. Camp and E. John Sadler,
Coastal Plain Soil, Water and Plant
Research, Florence, SC, telephone (803) 669-5203 U.S. Department of Agriculture | |