Professor recognized for work in statewide soil survey

Special to the E-T
Representatives from Natural Resource Conservation Service (NRCS) recognized one of Tarleton's professors for his cooperation with the Texas statewide soil survey. Pictured (l-r) are Dr. Ashley Lovell, head of the Department of Environmental & Agricultural Management; NRCS soil scientist John Sackett; Dr. Donald McGahan, assistant professor and NRCS cooperator honoree; Dr. Don Cawthon, dean of the College of Agricultural & Environmental Sciences; and NRCS soil scientist Sidney Paulson. Courtesy Tarleton State

The massive statewide soil survey which began in 1899?coincidentally, the same year John Tarleton College was founded?has officially concluded and, to celebrate, Texas’ soil scientists undertaking the Natural Resource Conservation Service (NRCS) recently recognized dozens of cooperators who dug, analyzed, inventoried and mapped their findings.

Among those involved in the 172 million-acre soil survey was Tarleton’s own Dr. Donald McGahan, assistant professor of environmental and soil science. On Aug. 29 representatives from the local NRCS office recognized McGahan, a faculty member of the Department of Environmental and Agricultural Management who has a joint research appointment with the Texas AgriLife Research Center in Stephenville. Officials presented him with a silver shovel and a framed copy of Gov. Rick Perry’s proclamation marking the “Last Acre” of the survey.

The NRCS, an agency of the U.S. Department of Agriculture, oversaw the statewide soil survey and collaborated with agencies and universities across Texas to complete the 111-year project. Soil scientists and other NRCS cooperators sampled soil from every acre in each of the state’s 254 counties, with the symbolic “final shovelful” dug near the NRCS’ headquarters in Temple in November 2010. The “last acre” of the soil survey is actually on private land between Van Horn and Dell City in Hudspeth County.

“Serving as a cooperator with the NRCS is rewarding personally and professionally,” said McGahan. “Since Tarleton is an educational institution the modest services we have provided to the soil survey efforts are accomplished in tandem with the mentoring of students in experiential learning.”

McGahan was involved in the soil survey for five years, primarily sampling the soils of north central Texas. Teams of Tarleton students assisted with the processing of the samples. According to the NRCS, Tarleton was among the top three providers of samples for the statewide soil survey.

Completion of all 254 counties is a tremendous milestone, said Dennis Williamson, Texas state soil scientist for the NRCS.

“Normally you’ll find 40 to 50 different soil types in every county,” Williamson said. “Using aerial photography, we record where the different soils occur on the land. Then we take all the information, send samples to the laboratory or test it locally. We analyze how much sand or clay is in the soil, also the amount of lime and the pH or acidity, of the soil.”

Once those analyses are done, soil scientists draw conclusions from the results found at the various sites, creating a map of the state’s terrain and providing valuable information. “We can determine soil capability for septic tank systems or building homes. These maps are helpful to determine the best location for roads or buildings, planting gardens or deciding what type of crops to plant and how productive the land will be,” added Williamson. “Ranchers can also use the maps to decide how many head of cattle they can run on their acreage, depending on the soil’s productivity.”

For more information and to view maps of the Texas soil survey, please visit: