Brian Schack, U.S. Department of Agriculture. Public domain, via Wikimedia Commons
Contributed by Ron Francis, NRCS Public Affairs Specialist, Utah.
For irrigated crops, knowing when and how much water to apply has long been a matter of experience and guesswork. In a changing climate, new technology can reduce this uncertainty, enabling farmers to make every drop of water count.
Stressors and impacts
Utah dairyman Dee Waldron watches the weather like a hawk. He wants up-to-date weather and climate information now, in the field, and in a clear way that helps him make critical farming decisions, such as when to irrigate, plant, and harvest. Waldron operates a dairy and feed grain farm in Morgan County, Utah, just east of Salt Lake City, which is considered a high mountain desert and not very productive without mountain streamflows stored in irrigation reservoirs.
“Before, I used to take a shovel in the field, dig down, and guess by feeling how much moisture was available for my crops,” said Waldron. “Now, I use my computer and smart phone to access the local weather forecast, the amount of soil moisture, the snow levels in the mountains, the amount of water in the river, and even the soil temperature. This really helps us as agricultural producers.”
As climate warms and a higher proportion of precipitation falls as rain rather than snow, the amount of water available for Waldron’s operations may decrease in some seasons. Knowing exactly how much water a crop needs and how much will be left for his dairy cattle can help Waldron set priorities on how he will use water.
SCAN system helps farmers know when and how much to water
In recent years, the U.S. Department of Agriculture has stepped up to make weather and climate data available to help reduce the risks to production agriculture. As a long-time cooperator with USDA’s Natural Resources Conservation Service (NRCS), Waldron was quick to agree to establish a Soil Climate Analysis Network, or SCAN, site on his farm in 2007. He and his neighboring farmers now have quick access to hourly data transmissions on soil moisture and temperature collected at 2, 4, 8, 20, and 40 inches below the ground surface as well as air temperature, solar radiation, relative humidity, wind speed, wind direction, and precipitation.
“The SCAN data has helped me determine the optimum time to water and as a result, last year I had the best corn crop I’ve ever had on this farm,” said Waldron. “I can sleep better at night knowing I can get up early, check the dew point on the computer, and decide if it’s the right time to bale my hay,” he added.
In the last decade, the NRCS National Water and Climate Center and National Soil Survey Center have worked with NRCS state offices to install more than 400 SCAN sites throughout the nation, with 38 in Utah. NRCS used geographic information systems, or GIS, to identify potential SCAN sites. They sought sites that would complement existing climate data, were located near irrigated agricultural areas, and represented benchmark soils. Working with local NRCS district conservationists, potential co-operators were contacted and agreements signed allowing the installation of the SCAN towers on their property.