Farmers Use Satellites to Boost Efficiency in Cultivating Crops : Agriculture: O.C.’s Rockwell is adapting weapons technology to ‘precision farming.’

A revolution is under way in Dennis Lindsay’s cornfield.

Inside the cab of his red Case tractor, a green light glows and a monitor screen winks. With all gear ready, Lindsay rolls his tractor down the rows of black soil as a computer directs a fertilizer spreader to drop a little more here, a little less there.

Agriculture is being reinvented for the 21st Century, and companies such as Deere & Co., Case Corp., Agco Corp. and Rockwell International Corp. are among those retooling.

Military satellites and space-age electronics are being brought down to earth and applied to agriculture. On-board computers and color-coded digitized field maps are deployed to help farmers cut costs, stay competitive and pollute less.

“I wouldn’t farm without computers any more than I would without a tractor,” said Lindsay, 45, who tills 1,435 acres of corn and soybeans in northeast Iowa.

Precision farming, also known as site-specific farming or farming by satellite, “is the next revolution in agriculture,” said Pierre C. Robert, a University of Minnesota soil scientist. “It’s exploding everywhere.”

To be sure, the technology can add 2% to 3% to production costs, on average. As the industry matures, experience and competition will control costs, experts say.

Precision farming technology is like spot-treating the field to make more efficient use of seeds, fertilizers, weed and bug killers--after soil fertility, organic nutrients, moisture and other variables are taken into account.

The most surprising entrant is Rockwell International Corp. of Seal Beach. The nation’s 15th-largest defense manufacturer sunk $6 million into the guidance technology of Desert Shield to make it work in the cornfield.

Rockwell’s “Vision System” of hardware and software will be unveiled at its avionics division in Cedar Rapids, Iowa, on June 23. Fifty-three farmers tested equipment on 50,000 acres of corn and soybean fields last fall.

The whiz-bang technology works like this: Signals from Defense Department satellites 11,000 miles above earth pinpoint a tractor moving through the field. An on-board receiver sends the field location to a computer, where it’s recorded. The reading is accurate to within three feet.

During the fall, a combine’s portable computer, called a “yield monitor,” records the amount of harvest every few feet. In the spring, the lunchbox-size computer “reads” the same location and directs sensors to vary the amount of seeds dropped or chemicals sprayed.

Three years ago, a few hundred farmers dabbled in the technology; now, 5,000 are using some of its techniques on 3 million acres, 0.8% of the nation’s total cropland. In a decade, half of all cropland will be farmed this way by the 300,000 to 400,000 farmers who produce about 80% of all U.S. food and fiber, the Agriculture Department says.

The $50-million annual business could soar to a $7-billion industry in five years, Jess Lowenberg-DeBoer, agricultural economist at Purdue University, figures. “We’re kind of at the steam-engine stage now,” he said.

Deere & Co. of Moline, Ill., the world’s largest farm-equipment maker, has plunged in with “a significant, multimillion”-dollar investment, said Adel Zakaria, a Deere vice president. He wouldn’t elaborate.

The 158-year-old company plans a debut this fall with equipment to retrofit its combines. Next year, a package of precision farming equipment is planned for Deere tractors, planters, sprayers, drills and combines.

“We’re just seeing the very beginning; the level of interest has far outpaced our expectations,” Zakaria said, as federal farm subsidies fall and farmers search to boost crop yields and trim seed and chemical costs. “It’ll be a major contributor to the evolution of agriculture.”

Rivals, such as Case Corp. of Racine, Wis., also are jumping into the field. The second-largest farm equipment maker says is spending a “significant amount” of its research budget to produce yield monitors for Case combines, said spokesman Bill Masterson. Tests are planned this fall.

Agco Corp. of Duluth, Ga., calls itself the leader in precision farming because technology was first installed in its European combines in 1992, ahead of other equipment makers. It plans to unveil U.S. products for its combines, tractors, planters and sprayers next year, following tests.