The coupling of overhead, mechanized irrigation systems with conservation tillage has resulted in the most exciting melding of technology and production agriculture Jeff Mitchell has seen in his University of California career.

Mitchell, cropping systems specialist in the plant sciences department, persistently has researched and demonstrated for at least a decade in an attempt to make pure, no-till farming part of California agriculture. It has been a struggle, although he has gained followers among some of the leading San Joaquin Valley farmers.

Long before Mitchell began preaching his no-till gospel, California farmers had reduced tillage, albeit slowly, largely for cost savings. They had done it with implements that performed several tasks in one pass. They had done it by adapting tillage equipment designed for drip irrigated farming.

Drip or micro-irrigation, introduced into California in 1975, has reduced tillage greatly in trees and vines, since furrow irrigation was replaced by low volume drip.

Drip has also made huge inroads into field crops, primarily for high value crops like tomatoes and vegetables, again minimizing the need to cultivate as much with furrow or check irrigation.

One of the biggest roadblocks to reducing tillage on row crops like wheat, corn, cotton, and alfalfa is the need to control irrigation water with beds or checks. Several years ago Monsanto made a major effort to get growers to switch to no-till with Roundup Ready cotton. It did not work since cotton requires beds to control water and cultivation to manage irrigation water. Growers readily adopted the herbicide-resistant biotechnology, but not no-till farming.

However, new fundamentals have befallen California agriculture that are forcing the new paradigm Mitchell talks about. The costs and availability of labor and water are forcing growers to become more efficient than ever in field crops.

Enter overhead mechanical irrigation. It, Mitchell says, offers “tremendous potential” of coupling conservation tillage with mechanized pivot or lateral irrigation, while reducing water use at the same time. There are no furrows or beds with overhead irrigation.

Mitchell made his observations at a symposium sponsored by Valmont Irrigation during World Ag Expo.

Mechanical, overhead irrigation systems date to the 1950s and were introduced into California then. Pivots and linear irrigation systems have been used since, but have never been a major irrigation technique, primarily because they could not be adapted to California’s heavy and irregular soil types.