California: Steady As She Goes

John Diener, a San Joaquin Valley grower, is definitely encouraged by the information he’s garnering through precision agriculture, but that doesn’t mean he’s prepared to jump in with both feet.”We’re not going crazy, but we’re moving on it,” he says. “I do think it’s helpful; I just want to get a better feel for exactly what it will do for us.”


Diener is a highly unusual grower even by California standards, where an astounding 350-plus agricultural commodities are produced. Nearly all growers of specialty crops — California produces more than half the nation’s fruit and vegetables — either grow so-called “permanent” crops such as tree fruits, nuts, or grapevines, or seasonal field crops, such as lettuce, cotton, or alfalfa. Diener farms about 4,500 acres, which is a fair amount in the Golden State, where productive farmland generally doesn’t come cheap, even on the West Side of the San Joaquin Valley. But it’s his crop mix that really makes Diener unusual: 1,200 acres of tomatoes (for canning), 300 of garlic, 150 of melons, 100 of spinach, 450 of almonds, 300 of grapes, 300 of white corn (for tortillas), 600 of alfalfa, 600 of wheat, and the balance, about 500 to 700 acres, are in cotton, depending on the year.

Diener plans on implementing precision agriculture crop by crop. With the help of Britz Fertilizers, he’s doing yield mapping on cotton and alfalfa. He plans on applying fertilizers to those fields with a variable-rate unit this fall, based on what the yield maps reveal. If that pays off, he will explore employing the technology on other crops.”We’ve got to see some results first, some payback on our investment,” says Diener. “Besides, you have to walk before you can run.”

Diener is also utilizing precision agriculture to reclaim land on his Red Rock Ranch that is plagued with drainage problems which has led to a buildup of salts. Through a project in cooperation with the Center for Irrigation Technology at California State University-Fresno, an instrument is being used that measure the soil’s electrical conductivity, essentially mapping the soil’s salinity. Diener than uses those maps to reclaim the soil through tilling, which involves installing tubes that push the salts out of the soils.


Diener employs several pest control advisers who utilize precision ag, including Tony Oliveira, the operations supervisor for the Five Points, CA office of Western Farm Service. Oliveira keeps five AutoFarm GPS units — mounted on Caterpillar Challengers of various horsepower — busy 24 hours a day, seven days a week from September through November. It is then that the soil beds must be listed, before the winter rains hit the Golden State and make the ground too wet to work.

Oliveira is most excited about the variable-rate units. He used a Mid-Tech Legacy 6000 from Linco Equipment, but is also encouraged by new offerings from Raven Industries and CDS-John Blue. Poor drainage is a critical problem on the valley’s fertile West Side, so growers are using variable-rate technology to apply gypsum to increase water penetration, says Oliveira. “We’re seeing more and more variable-rate technology,” he says. “It’s really picking up momentum.”

Editor’s note: This article first appeared in the Winter 2004 issue of PrecisionAg Special Reports.

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