California’s historic drought is causing public and private sectors to make difficult and drastic choices between land uses and water needs. Researchers and Extension specialists in Tennessee plan to develop a model of much of Tennessee's water use and suggest management changes that may affect water availability in Tennessee and across the Southeast. The idea is to transform usage patterns before climate change will cause unplanned changes to the region’s agriculture and way of life.
 
A new five-year $4.9 million study funded by the USDA proposes to model how changes in temperature, droughts and flooding will affect land use in the Tennessee and Cumberland River basins. Further, the study will examine how changes in industrial and consumer demand for the water will affect its quality and availability for agricultural uses. Led by Forbes Walker, an environmental scientist with the University of Tennessee Institute of Agriculture, the effort includes researchers from other institutions of higher learning and public and private entities across the state. The grant was announced on April 7, with an award of $900,000 for the first year’s funding.
 
“It’s a broad-based, far-reaching effort to address a serious concern,” said Walker. “The reasons for climate change can be debated ad infinitum, but the region’s weather patterns are changing. The question is ‘What are we going to do to address it?’”
 
Walker and his colleagues will specifically study water use and agricultural production in the Tennessee and Cumberland River basins and promote the adaptation of agricultural practices best suited for anticipated climate-related changes in water availability and growing conditions. “In the last 20 years differentiations in the timing and intensity of rainfall events and other subtle changes in the region’s climate have been recorded. Our study poses and hopes to answer such fundamental questions as ‘How can agriculture adapt to these changes?’ and ‘What policy, institutional, or technological changes will help ensure that water is available to meet overall demand?’”
 
The Cumberland River Basin is of particular interest to the researchers because of the area’s diversity of agricultural practices – from row crops to animal production to plant nurseries and forested tracts. The problem is complicated further by the range in sizes of those operations – from small family farms to large-scale cattle operations and production forests as well as related processing industries. Also of interest is the intersection of these traditional farming enterprises with Nashville, which is among the nation’s fastest growing metropolitan areas.
 
“Dramatic changes in water use are already occurring in the area, and further climate change may pose significant challenges to traditional methods of water allocation,” said Walker. “The findings of this study should help Tennessee and Southeastern farmers and communities make intelligent water use decisions before they face a crisis situation.”
 
The project expects to take advantage of existing research and educational infrastructure to address four tasks:
  • develop a range of anticipated climate and land use scenarios for the southeastern U.S.
  • couple a suite of physically-based, spatially-distributed hydrodynamic and biogeophysical models
  • use the scenarios, coupled models and field trials conducted at University of Tennessee AgResearch and Education Centers to test the effects of adaptive farm management practices (AMPs) on watershed-scale hydrology
  • determine how changes in water availability affect farmer willingness to adopt AMPs, farm profitability and rural economies.
The model for Tennessee will be scaled up for use on a regional scale and the scientists expect to integrate their study into faculty- and student-led outreach efforts designed to enhance agricultural practices within the framework of water use policy.

The project is officially titled “Increasing the Resilience of Agricultural Production in the Tennessee and Cumberland River Basins Through More Efficient Water Resource Use," and was funded through USDA’s Water for Agriculture initiative. In addition to UTIA’s Walker, other project scientists and their responsibilities in this project include Thanos Papanicolaou, UT Knoxville engineering professor who will lead the hydrological modeling group; Song Cui and Warren Gill of Middle Tennessee State University, who will oversee undergraduate education efforts in Middle Tennessee; Paula Gale and Greg Nail, faculty with UT Martin who will lead undergraduate education efforts in West Tennessee; Alfred Kalyanapu of Tennessee Technological University who will guide the flood prediction modeling efforts for the Tennessee and Cumberland River basins; and Brian Waldron of the University of Memphis, who will lead efforts to predict changes to groundwater water with the expected increase in irrigation intensity in West Tennessee.

 
“If we can model regional climate change in the Southeast and help farmers anticipate and react to those changes, then we will be serving the interests of regional agricultural industry as well as society as a whole,” said Walker. “The ultimate goal remains profitable and sustainable agricultural practices.”
 
The scientists hope the study’s models and adaptive management practices can be applied to other regions experiencing climate change. 

UTIA researchers and Extension specialists are also working on a related USDA project documenting the actual water needs for agricultural enterprises in Tennessee, including dairy operations and plant nurseries. Led by Chris Clark, an agricultural and natural resource economist, the three-year, $644,000 effort also involves a broad range of specialists including Shawn Hawkins, an animal waste management expert with the Department of Biosystems Engineering and Soil Science, and UT Extension nursery crops specialist Amy Fulcher. Their focus is on developing recommendations to improve the water use efficiency of water-intense operations.