D.F. Heermann, G.W. Buchleiter, M.C. Blue, J.A. Chapman, and H.R. Duke
agriculture constitutes only 15 percent of cropland in the U.S., but produces 41
percent of the total crop sales. About one third of the approximately 50 million
irrigated acres are irrigated by center pivot sprinklers. These sprinklers are
familiar to many air travelers as the huge green (or brown) circles. With such a
large irrigated acreage, irrigation is a major user of water accounting for
about 80% of total water use in the U.S. Overirrigation causes excessive
leaching of nutrients and chemicals which degrade water quality. Irrigators as
well as consumers are concerned that this water be managed wisely to conserve
both its quantity and quality.
More than twenty years ago, this team
began developing methodology to determine when to irrigate and how much water to
apply with center pivot irrigation systems. They developed personal computer
(PC) programs for use by irrigators to
calculate crop water use from weather data. They developed a prototype
computerized monitor and control system as a convenient means of controlling and
monitoring irrigation systems to conserve water and energy. They have
aggressively pursued transfer of irrigation water management technology,
encouraging many other professionals to embrace the crop water use concepts, and
worked with the industry to improve the computerized monitor and control
systems. Now these technologies are used on an estimated ten percent of the
center pivot irrigated land in the U.S., saving an estimated 160 billion gallons
of water annually.
--A network of automated weather stations has been established to measure
factors that effect the amount of irrigation water needed for crop production.
State-of-the-art computer technology has been used to make this information
available to irrigators.
Irrigation Recommendations -- These weather data are processed to
determine how much irrigation water is needed and when it is needed. Twenty
years ago, recommendations were first put on answering machines, radio, TV,
and in newspaper articles. Today, they are placed on internet sites, and are
uploaded to commercial satellite services for direct satellite delivery to
more than 2000 farm offices.
Irrigation Monitoring and
- The team developed a prototype radio telemetry monitor and control system
in 1982, which monitored the positions and operational statuses of multiple
pivots on a farm.
Following successful implementation of this experimental
technology, they worked with industry to develop viable commercial products
that have computer capability to implement much more sophisticated control.