Controlled Environment Agriculture

Joanne Littlefield
Dec. 22, 2000

An increase to the bottom line is the goal of agricultural producers today, and they do that by continually seeking new and better ways to achieve peak performance and top yields from their crops. In many Arizona communities where prime agricultural land is being developed for housing or industrial use, agricultural production is sometimes forced out to locations with potentially poor soil, more expensive land and increased water costs.

Getting the most out of the plants by controlling such things as humidity, light and temperature has been achieved for years through the use of row crop covers, mulching and greenhouse production. Greenhouse production in the extreme is what the Controlled Environment Agriculture Program (CEA) at the University of Arizona is all about. Every aspect of a CEA plant's environment is analyzed and adjusted as needed. These include irrigation, nutrient uptake, lighting, carbon dioxide and humidity.

Students are cultivating and harvesting tomatoes, peppers and cucumbers. Additional classes are being developed in cooperation with faculty from other CALS departments including entomology, plant sciences and agricultural and biosystems engineering.

Gene Giacomelli, director of the CEA program, says that by combining sound plant science training with the technology of the future, CALS students will be an asset to Arizona employers. "We hope to teach and send to the workforce employees better able to solve production problems in a hydroponic growing situation where the environment is controlled through the marvels of engineering," Giacomelli says. Emphasis is placed on the design of cost-effective systems, processes and equipment that will generate high yields of quality produce.

Because bees are used to pollinate the crops, pest control strategies in the greenhouse emphasize natural methods. These include proper sanitation and cleaning, pest exclusion through barriers, and the use of beneficial insect predators, such as parasitic wasps.

There is an increased capital outlay in intensive greenhouse operations for buildings and hydroponic crop production systems. Economics are often the bottom line in the decision to build. Giacomelli notes that the profit differences between hydroponic production and traditional field cultivation are astounding."Yield data show that tomato production is 600,000 pounds per acre in the greenhouse versus 60,000 pounds per acre in the field or 60 pounds per plant in the greenhouse versus 6 pounds in the field."

Canada and Mexico have thousands of acres under greenhouse-protected cultivation, but it is a relatively new industry in Arizona. The state has only 200 acres of greenhouses, primarily in Cochise County. It has been estimated that more than $100 million has been added to the Arizona economy during the last eight years from the greenhouse hydroponic crop production industry.

Giacomelli says that in addition to classroom instruction and research, information will be provided to local growers through extension agents statewide, as well as through newsletters, workshops and an interactive web site.


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