By Pat Rorabaugh, Ph.D., Lecturer in the School of Plant Sciences and a hydroponic specialist with the Controlled Environment Agriculture Center, University of Arizona. The past 20 years have certainly seen some changes to Arizona agriculture; but the next 20 years will bring plenty more. A wide scope of opportunity in advancements exists.
Water conservation: Water is our most precious resource. Whether crops are grown in soil or hydroponics, water conservation must be at the forefront of Arizona agriculture. One way to conserve water is to put it right where it is needed by using drip irrigation. As an example, cotton is now being grown very successfully in Coolidge and Maricopa, Arizona using subsurface drip irrigation and drip is a standard practice for greenhouse growers.
Arizona Sun: Although water may be our most precious resource, light is our most abundant. In 20 years,Arizona has the potential to become the solar energy capital of the nation with solar energy farming. Just as farmers and ranchers across the Great Plains region of the United States also farm wind power (the turbines turn slowly over wheat fields or cattle pastures), farmers and ranchers in Arizona could be farming solar power. Solar technology has improved and with the current emphasis on alternative energies and future technological improvements, the costs of such systems will become more reasonable and the systems far more efficient.
For farmers, solar panels could be covering their homes, equipment storage buildings and shops as well as crop processing facilities. For ranchers, solar panels could provide much needed shade for animals. And, not to leave out city dwellers, solar panels should cover every home and building in Arizona. Solar electric could power everything from the toaster in the kitchen to the computers in the greenhouse; from the milking machines at the dairy to the combine in the field.
Water recycling: Why use water once when you can recapture it for multiple uses? Commercial greenhouse hydroponic growers do this now by recycling their nutrient solution. However, both greenhouse and field growers could also recycle water from the air itself. Water condensers in the field or the greenhouse could pull water directly from the air for use back in the greenhouse or field, according to studies conducted at the UA/CEAC on this method of water recycling. Water condensers are not a new idea and were even described in the 1970s science fiction movie Star Wars as “moisture vaparators” used on the mythical desert planet, Tatooine. The reclaimed water was used to grow crops in subterranean hydroponic farms!
Aquaponics: What about using the same water for two crops? Aquaponics is the technique for recirculating water between fish and plants to create a sustainable ecosystem. The fish are fed and then provide nutrient rich water upon which the plants thrive. As the plants take up the nutrients they return clean water to the fish. Tilapia is perfect forArizona since it is adapted to hot climates and has become a regular selection at most restaurants. Several crops can be grown with Tilapia including lettuce and basil, according to researchers that have studied optimal plant to fish ratios at the UA/CEAC.
Rain harvesting: Though we live in a desert, when it rains it can pour! Rain water is quality water without any contaminants that can be channeled from homes, buildings, barns, etc. and collected to provide fresh water for animals and crops. For greenhouses, this water could be used in the evaporative cooling system to supplement water from wells or city water supplies. For outdoor animals, this water could be used in misting shelters to keep the animals cool.
Other Alternative Energies – Biofuels & Biomass: Several crops have been looked at recently as possible alternatives to fossil fuels. One plant that shows real promise as a biofuel is algae (and unlike corn is not an existing food crop). Grown in various ways (tubes, raceways, ponds) algae is harvested, the oil extracted by compression and the residual biomass could be used as an animal feed. Also, leftover plant material from all sources could be pelletized and burned in biomass furnaces. Sunizona Family Farms in Willcox, Arizona has recently begun using pelletized pecan hulls to heat their greenhouses.
For more on algae, do a search on www.azfb.org using the key word “Algae.”
Protecting Crops from Diseases – Grafting. Grafting tomatoes onto vigorous, disease resistant root stocks has been a common practice in greenhouse production for years. However, melon farmers may benefit from grafting as well. They have serious problems with diseases in the field which can destroy a crop just before harvest. With methyl bromide on the brink of being banned, a UA / CEAC research group has had great success with grafting melons onto disease resistant root stocks and is currently conducting field trials withArizona farmers. As diseases become more prevalent, grafting may hold the key to successful production. Also, with year-round high light,Arizona has the potential to become a center for transplant production, producing high-quality grafted transplants for both field and greenhouse use.
Smart Technologies: Finally, smart technologies, including advances in mechanization, automation, robotics and remote sensing, will help Arizona agriculture stay competitive in a global environment by increasing efficiency and productivity.
What will Arizona agriculture look like in 20 years? I’ve mentioned just a few possibilities but one thing remains to be said. Any advancements in Arizona agriculture will only occur if the next generation has an opportunity for a quality education.
Well-educated agriculturalists and skilled technical support will be crucial. Education will be the key to unlocking a sustainable future forArizona.
Editor’s note: Dr. Rorabaugh teaches Introduction to Hydroponics and Controlled Environment Agriculture. If you have further interest in controlled environment agriculture and hydroponics go to www.ag.arizona.edu/ceac. This article is an updated and condensed version that originally appeared in Arizona Farm Bureau's monthly publication Arizona Agriculture.
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