A drone soars over a blazing hot cornfield in northeastern Colorado. It snaps images with an infrared camera. Researchers will use those pictures to decide how much water to give the crops the next day. They will analyze the images to look for signs that the corn plants are stressed from lack of water.
The U.S. Department of Agriculture (USDA) station is using technology to squeeze the most out of every drop of water in the Colorado River. That beleaguered waterway serves about 40 million people.
Remote sensors measure soil moisture and relay the readings by wi-fi. Cellphone apps collect weather data. Others calculate how much water different crops are consuming. Researchers deliberately cut back on water for some crops. They are trying to get the best harvest with the least amount of moisture—a practice called deficit irrigation.
In the future, tiny needles attached to plants could directly measure how much water they contain. Then computers would signal irrigation systems to switch on or off, based on those measurements.
Researchers and farmers are running similar experiments in arid regions around the world. The need is especially great in seven U.S. states that rely on the Colorado River. They are Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming.
The river supplies more than 7,000 square miles of farmland. It supports a $5 billion-per-year agricultural industry, according to the U.S. Bureau of Reclamation. That department manages most of the big dams and reservoirs in the Western states. The river also irrigates about 700 square miles in Mexico.
The problem facing lawmakers is how to divert water appropriately. They want to meet the needs of people in growing cities without drying up farms, ranches, and the environment. The researchers’ goal is to gain a precise understanding of crops, soil, and weather. With that knowledge, they hope to help farmers determine exactly when and how much to irrigate.
“We call it precision agriculture, precision irrigation,” says Huihui Zhang. She is a USDA engineer at the Greeley, Colorado, research farm. “Right amount at the right time at the right location.”
And there may be more benefits than just conservation. Blaine Carian grows grapes, lemons, and dates in Coachella, California. He already uses deficit irrigation. He says withholding water at key times improves his grapes’ flavor by speeding up sugar production.
For I will pour water on the thirsty land, and streams on the dry ground; I will pour my Spirit upon your offspring, and my blessing on your descendants. — Isaiah 44:3
