Precision agriculture, using global positioning system (GPS) technology, has taken many farming operations to a new level of accuracy.

A recent University of California study concluded it has also made farming faster.

A processing tomato production study conducted by a quartet of UC Davis researchers has shown that an autoguidance system using real-time kinematic (RTK) GPS is not only accurate within a half inch in agricultural production, but growers can cultivate at speeds as high as seven miles per hour and still not damage plants.

The study, conducted by S.K. Upadhyaya and D.J. Hills of the UC Davis biological and engineering department and graduate assistances A.Z. Abidine and B.C. Heidman, indicated that at those speeds, plants were not damaged with cultivator disk spacings of just two inches.

One of the first places GPS technology was utilized was on harvesters, where yield monitors mapped fields for yield to identify high and low producing areas. GPS/variable rate technology has been beneficial is in applying gypsum. At left, a spreader equipped with variable rate technology is loaded at a Kings County, Calif. farm.

In a companion test, the researchers also validated no significant damage to drip irrigation lines when fertilizer was shanked in within two inches of buried lines at 3.5 miles per hour.

In the trial at the Western Center for Agricultural Equipment on the UC Davis campus, the test plot was listed into 60-inch beds with the autoguidance technology. This was followed by cultivation to remove weeds, followed by an application of a pre-emergence herbicide with a power incorporator.

The trial was conducted with both tomato transplants and seed. There was no damage during cultivation; however, researchers found it is critical to carefully adjust implements, since they are working much closer to plants with GPS autoguidance.

The only drip tape damage came where the soil was hard and dry. In that situation, tape was damaged when the shank followed prevailing soil cracks rather than cutting the hard soil. The shank actually bent and cut the buried drip tape.

Researchers said this could be avoided with a more rigid shank or more favorable soil moisture conditions.

This is just one area GPS/precision agriculture is being utilized. Not only are autoguidance systems now widely used, but GPS technology and aerial/satellite mapping are being utilized in a wide array of variable rate technologies.

It’s called “prescription agriculture,” with maps created to identify conditions in various sections of a field and application rates of everything from seeds to fertilizer automatically varied to meet those conditions.

And it’s all done by computers and no-hands satellite guidance of tractors.

This new technology has come about with the advent of civilian use of global positioning satellites once reserved only for military use. This opened the possibility of locating any object on the surface of the earth.

High-end, ultra-precise GPS systems can provide accuracy within 0.4 inches on-the-go.

Despite the cost of up to $50,000 for RTK GPS tractor guidance systems, farmers have rapidly adopted the technology because of the accuracy and speed it affords.

Farmers have documented significant savings in time, fuel, labor costs and production inputs, as well as increased yields and improved crop quality.