What is in this article?:
- In the U.S. West and Southwest, large-scale farms struggle to survive economically amid chronic drought conditions and increasing costs for surface water.
- Utilizing high tech solutions to improve yield with less irrigation water is a challenge taken seriously by scientists at the USDA Agricultural Research Service’s U.S. Arid Land Agricultural Research Center at Maricopa, Ariz.
- Scientists are utilizing an arsenal of high tech remote sensing tools to determine specific plant needs in large-scale production agriculture.
DOUG HUNSAKER, Agricultural Research Service agricultural engineer, works on precise irrigation scheduling in a cotton trial (ARS photo).
“The project utilizes remote sensing for total field management,” says ARS Agricultural Engineer Doug Hunsaker, the project’s lead scientist.
“The solutions found in irrigation could also be applied to increasing crop yields, while minimizing agricultural chemical transport off irrigated fields through site-specific applications of fertilizer and pesticides.”
In the cotton trial, neutron probes record soil moisture and actual crop water use, or evapotranspiration. Soil moisture is measured to three meters under the soil surface. A commercial ETgauge measures plant evaporation at the top of the canopy.
Evapotranspiration is also recorded by micrometeorological stations. Heat shed by plants is calculated by a scintillometer, an instrument that measures shimmering light similar to that seen from heat waves over hot pavement. Wireless-networked thermal radiometers detect crop water stress.
Images from the equipment are collected using a remote sensing system onboard a helicopter flown across the field at two week intervals. It’s hoped the image data can help implement practical and low-cost ways to model crop water use over an entire field.
“The remote sensing system aboard the aircraft includes a multi-spectral camera, which collects light primarily in the red and infrared wavelengths,” French says. “A thermal infrared camera records the surface temperature.”
Remote sensing is hot technology in agriculture worldwide. Future NASA satellites will include advanced sensing technology to more accurately record water use regionally and globally, including on irrigated land.
“Remote sensing information is vital for creating decision support tools which will help farmers achieve long-term prosperity,” French says.
Helicopter use to gather remote sensing data is not practical or affordable for farmers, but it is invaluable for research. Tractor-based and other ground-based sensor systems currently under development can collect remote sensing-like information at much lower costs.
“Hopefully when the dust settles in about 10 years many of the tools and satellite data will be affordable for farmers,” French says.