Controlled Environments Growing in Popularity
University of Arizona plant scientist and professor emeritus Merle Jensen labeled controlled environment agriculture the “birth of an agricultural revolution.”
A popular response to today’s consumer demand for fresh, healthy, locally grown vegetables, the concept of greenhouse crop production is expanding and now makes a nearly $12 billion contribution to the production food chain.
“Twenty-five years ago, the only people who wanted to talk to me about greenhouse growing were the marijuana cultivators, but that’s all changed now,” Jensen said.
After decades in the emerging industry, he said, “I sometimes feel like a horticultural missionary.”
As early as 1965, Jensen thought it a good idea to try putting air and heat into 150-foot-long row covers and adding water and fertilizer through what he initially termed a “do hose,” which we know today as drip irrigation.
Large-scale growers are converting portions of their fields to controlled environments, and smaller farms are adapting glasshouse technology. Even backyard vegetable growers are setting up mini-operations to keep out pests, lower irrigation costs, harness sunlight and maintain a year-round operation that can avoid freezing temperatures, according to Jensen.
It’s not a new concept. The earliest protected-environment food production is believed to be off-season cucumbers grown “under transparent stone” for Roman Emperor Tiberius. Egyptians and Babylonians grew edible munchies in water gardens some 3,000 years ago, as noted in historical archives.
Up until the mid-1900s, the standard farm routine remained relatively unchanged: dig a hole, plant a seed, water and feed it, pick out unwanted weeds, then harvest the crop and enjoy it. Fast forward to today’s greenhouse or hoop house growers, who now grow in enclosed soil beds or hydroponically.
“It’s growing plants in a solution of water and fertilizer, with or without the use of an artificial medium like sand or peat moss or coconut coir,” Jensen said. “The choice to move farming indoors and grow (controlled environment agriculture) is obvious. We have control over every part of the operation, and can get yields of 10 to 20 times more per square foot. We’ve broken the sound barrier in growing vegetables in greenhouses.”