Uvalde center's water conservation research may have national, international applications
Intensifying drought conditions in Texas and other parts of the U.S. coupled with growing worldwide water consumption make water conservation research at the Texas AgriLife Research and Extension Center in Uvalde even more relevant, said the center's director.
"Our research program includes methodology on how to augment aquifers, ways to determine their uniqueness, and methods to increase the efficiency of water drawn from them," said Dr. Bill Holloway of Texas AgriLife Research, resident director of the center. "We have several ongoing research projects tied to water conservation."
Holloway said the current drought likely serves as an example of what producers in many other areas of the nation will experience as normal future water availability, adding that crop irrigation represents the single-largest area of water consumption in Texas.
"The majority of the water used for irrigation in Uvalde County and surrounding counties comes from two large but dissimilar underground water sources--the Edwards Aquifer and Carrizo-Wilcox Aquifer," he said Holloway said the center works closely with area producers to identify ways they can reduce their irrigation water use and, when necessary, meet watering restrictions, and still have good crop yield and quality.
He pointed to the center's Precision Irrigators Network, which began in 2004, as an example of long-term researcher/producer cooperation toward water conservation.
The network is comprised of about 20 producers in a multi-county area of South Central Texas and supported by several regional water providers and conservation districts. Producers work with center researchers and Texas AgriLife Extension Service agents to gather data on rainfall and climatic factors, soil type, soil moisture evaporation and the growth stages of various crops in an attempt to develop methods to increase irrigation efficiency.
Results from the network have demonstrated opportunities for reducing irrigation use by 15 percent to 25 percent without reducing crop yield or quality, according to program researchers.
"The network was formed with the goal of saving millions of gallons of water annually by reducing irrigation water use by as much as 20 percent in the future," Holloway said. "We're well on the way to accomplishing that goal."
Dr. Diane Rowland and Dr. Daniel Leskovar, both AgriLife Research scientists at the center, provide leadership for the irrigators network.
Rowland said in addition to current research, new program research will be expanded to include enhancements on weather data gathering capabilities, improved technology for taking seasonal root measurements and using sap flow to determine water use by different crop plants.
"There's also a real opportunity for growers to learn more about and adopt conservation tillage techniques," Rowland said. "Conservation tillage hasn't been very well established in this region, but it's a tremendous water-saving tool and the drought should convince farmers here and elsewhere that it's worth pursuing."
Rowland is also working on research related to alternative irrigation methods, including surface- and subsurface-drip irrigation, as well as the use of drag socks on pivot-irrigation systems.
"These will all have applications not only to this region, but to other regions in the U.S. and to other nations where there are similar soils, water sources and watering restrictions," she said.
Dr. Jason West, another of the center's AgriLife Research scientists, is an ecosystem ecologist studying the other end of the aquifer water balance equation. West is investigating range management methods to improve aquifer recharge, as well as ways to determine the nature and distinctiveness of aquifers.
"This includes investigating the relationships between water bodies in the South Central Texas area, particularly those which supply much of the region's irrigation water--the Edwards Aquifer and Carrizo-Wilcox," he said.
West is evaluating the non-radioactive stable isotopes of well water to understand the relationships between wells and the aquifers supplying them.
"Stable isotopes record the evaporation and condensation histories of water and naturally 'label' different water bodies," he explained.
West said his research would lead to a better understanding of how the aquifers are organized below ground.
"This allows us to know more about this unseen and complicated network of water resources and to evaluate the consequences of our activities on these water bodies," he said.
West said isotopic signatures, combined with other measurements, help to determine the distribution and efficiency of recharge into underground water bodies such as aquifers.
"It helps us determine how much water actually makes it past plant roots and into the aquifer system," he said. "It also shows us how recharge differs in a karst or limestone-based aquifer like the Edwards as opposed to a semi-consolidated sediment structure like the sandy sediments of the Carrizo-Wilcox."
West said data obtained on the two regional aquifers would help better understand and manage similar bodies in the U.S. and throughout the world.
Information derived from this research will be useful in helping water districts develop "desired future conditions" they want to meet, he said.
"In the future, aquifers in this region and throughout the U.S. will come under increased pressure to facilitate economic growth," Holloway said. "What researchers learn now about efficiently managing water resources will be vital in addressing the challenges of ensuring an adequate supply of this precious natural resource in years to come."