In the face of drought in California and the Plains, growers are looking for ways to make the thriftiest use possible from the scarce water supply, says Ensia, describing research on how to nurture crops without wastage. In Texas, USDA research engineer Susan O’Shaughnessy is developing sensors that measure the temperature of the leaf canopy of crops, a way to gauge the need for water. The sensors ride on center-pivot irrigation booms.
“In O’Shaughnessy’s system, an onsite computer – the brains of the $3,000 system – processes data from the infrared sensors along with weather information,” says the story, which was co-published by Civil Eats. “The computer compares these data against stress thresholds for that particular crop to determine how much to irrigate.” Different zones of the field may get different amounts of water.
Researchers in Australia are working on “high performance” surface irrigation that releases a more limited quantity of water and at a higher rate than traditional flood irrigation, writes reporter Matt Weiser. The goal is to prevent water from sinking below the root zone of the crop or overflowing the boundaries of the field. A study completed in March found that the approach reduced water loss and improved nitrogen uptake by crops.
“Another new technology being used in California, primarily with drip irrigation, measures actual evapotranspiration – the movement of water from soil through plants to the atmosphere – on an entire farm field,” says Weiser. The technology has been used on a smaller scale but can be imprecise when extrapolating the data to cover an entire field. With a measurement of losses from evaporation, growers can decide if plants need water and how much.