Automation Can Save Irrigation Water and Keep Groundwater Clean

For the past four summers, cotton plants on a test site in Lubbock, Tex., have had all their water needs met by computer, with no waste of water or fertilizers and other dissolved chemicals.

The computer decides whether to turn on irrigation pumps based on readings from soil probes, combined with weather updates every half hour plus information from a computer model on crop water use. The prototype, still in the research stage, is believed to be the only such totally automated irrigation management system in the country.

Steven R. Evett, a soil physicist with the Agricultural Research Service in Bushland, Tex., designed a key component of the system: the electronic probes that give the computer soil moisture readings on the half hour. He also wrote the computer program that drives the soil moisture readings.

A Texas A&M University team in Lubbock, led by soil physicist Robert J. Lascano, wrote programs that combine water content and weather data and automatically make irrigation decisions.

Dynamax, Inc., a Houston firm that sells and manufactures scientific instruments, sells the probes. Working with the company and Evett, Lascano has demonstrated the workability of joining the probes with a field weather station and the computer model of crop water use he designed. Evett adapted the model for personal computers and continues to update it. The model can be downloaded from the World Wide Web at:

http://www.cprl.ars.usda.gov/programs/

An article on the system appears in the January issue of ARS' Agricultural Research magazine. The article also is on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/jan98/prob0198.htm

Scientific contact: Steven R. Evett, USDA-ARS Conservation and Production Research Laboratory, P.O. Drawer 10, Bushland, Texas, phone (806) 356-5775, fax 356-5775, srevett@ag.gov.