Field with drought.

Spot droughts are one of the biggest frustrations for farmers, who may miss out on federal assistance payments.

Photo courtesy Laura Warner

A two-year, $600,000 grant to create a more accurate analysis of soil moisture for drought depiction, agricultural assessments and flood potential has been awarded to the interim dean of the College of Science at The University of Alabama in Huntsville (UAH), a part of the University of Alabama System, by the National Oceanic and Atmospheric Administration (NOAA).

Interim UAH Science Dean Dr. John Christy is a distinguished professor of atmospheric science and director of UAH’s Earth System Science Center (ESSC). He’s also the Alabama state climatologist and the grant’s principal investigator. Dr. Christy says his research team will make use of Alabama’s existing climate stations.

“We will deploy state-of-the-art sensors at our 16 Alabama climate stations, along with other types of sensors for cross-validation, that will aid in producing consistent measurement values because these various sensors are used throughout the nation,” Dr. Christy says. “To fill in the area surrounding the point measurements, we will develop and improve remote sensing soil moisture products using satellites and drones.”

The system under development would especially aid farmers seeking federal assistance payments, as the region is prone to flash droughts that can decimate pastures and crops over a wide-ranging, spotty area.

“We had a serious flash drought in September 2019 that devastated pastures in Alabama, Georgia and north Florida that supported our livestock industry,” Dr. Christy says.

Dr. John Christy

The research will provide a more accurate depiction of the stresses that crops and livestock experience and be an additional indicator of agricultural losses, says Dr. John Christy.

Michael Mercier / UAH

“The typical metrics for determining stress for federal assistance payments relied on tools that did not capture this event, so many livestock producers were not eligible for assistance,” he says. “This work will provide not only high resolution but a more accurate depiction of the stresses that such crops experience and thus be used as an additional indicator of agricultural losses.”

Dr. Christy’s team is Dr. Walter Ellenburg, ESSC research engineer; Dr. Vikalp Mishra, ESSC research associate; Dr. Udaysankar Nair, associate professor of atmospheric and Earth science; Dr. John Mecikalski, professor and chair of the Department of Atmospheric and Earth Science; Dr. Christopher Hain, research scientist, Short-term Prediction Research & Transition Center (SPoRT), Earth Science Branch, NASA Marshall Space Flight Center; and Cameron Handyside, ESSC research engineer.

Currently, much of federal drought assistance for farmers is based on U.S. Drought Monitor status, says Handyside.

“The problem with the Drought Monitor is that it is a conglomeration of many factors that go into a general drought condition,” Handyside says. “Conditions like long-term streamflow, or municipal water restrictions, or precipitation over the last month, or many more, all go into making one drought map.”

While that’s a good indicator of general drought, the Drought Monitor does not always reflect agricultural drought, Handyside says.

“Spot droughts are one of the biggest challenges facing farmers in Alabama. Alabama can go from flood to drought in seven days and often the Drought Monitor is slow to respond,” he says.

Much of the Drought Monitor data is reported at the county level, yet conditions can vary widely across a county.

“We see cases where a farmer in northern Madison County is doing great, plenty of rain and so on, while farmers in the southern part of the county have not seen a drop of rain in weeks,” says Handyside. “We believe that agricultural drought is driven mostly by soil moisture and that a high-resolution map of recent and current soil moisture is a better indicator of crop stress that leads to agricultural drought.”

Soil moisture monitors installed at the climate stations under the grant will have an accuracy of ± 1%. Each station will record soil moisture at three depths – 5 cm, 20 cm and 50 cm – for direct comparison with the standard measurements at the NOAA and U.S. Department of Agriculture (USDA) Natural Resources Conservation Services reference sites. Soil samples will also be collected and analyzed from each site.

One project goal is to evaluate low- to moderate-cost sensors to determine reliability and how well the data returned compares to more expensive sensors used by USDA and NOAA.

In addition to the climate stations, sensors will be installed at North Alabama sites used by Baron Services. Where available, stations will use electric power and internet service, but otherwise stations will be designed to be independent of power or internet, using cell service and solar to power internal batteries.

“We will also reach out to the agricultural research stations around the state,” Handyside says. “Once we have a reliable and resilient instrument, we will reach out to other potential sites.”

The sensor network will be used to develop, test and calibrate remote-sensed and model products that must be calibrated regionally.

“Alabama soils and weather make the state much different than conditions in the Midwest or Plains states, where so much of the soil moisture research is conducted,” Handyside says. “The remote-sensed and model data from satellites, drones and crop models are intended to fill in the gaps between the sensor stations and create a more complete picture of current soil moisture conditions in Alabama.”

As well as the Alabama research, the overall NOAA funding incorporates separate but cooperative projects in Georgia and Florida. In the other two states, the research is being done by the University of Georgia Agricultural Research Center in Tifton, the Florida state climatologist at Florida State University and the University of Florida.

“Each state is responsible for their own information,” Handyside says. “However, as part of the Alabama project, we are working to develop an online repository that will allow access to sensor data and maps.”

The Alabama research will be made available to the National Soil Moisture Network's effort to standardize soil moisture data.

“The USDA is also very interested in soil moisture and agricultural drought designations, so we hope to work with the USDA National Agricultural Statistics Service office in Alabama, since they are responsible for publishing crop progress reports,” Handyside says. “We have had success working with them in the past to provide data to help them develop a clear picture of conditions during the growing season.”