The Natural Resource Conservation Service (NRCS) is conducting an initial soil survey in McMullen County. The survey is expected to be completed by the fall of 2010 and will provide a detailed report on the soils of McMullen County. The soil survey will have maps with soil boundaries and photos, descriptions, and tables of soil properties and features.

“The soil survey of McMullen County will be the last chapter written in a long history of soil surveys in South Texas based on county boundaries,” said Clark Harshbarger, head of the soil survey team for McMullen County.

Soil surveys are be used by farmers, ranchers, real estate agents, land use planners, engineers and others who desire information about the soils in their county. For the farmer or rancher, the soil information can be used in conservation planning, grazing or crop production and even fence building. Real estate agents can use it to let potential buyers know where the best soil is for building a house, installing a septic system, or putting in a pond. Builders or land use planners can utilize the soil survey for planning developments or building placement.

Soil surveys are the foundation of conservation planning work conducted by NRCS with landowners across Texas. Soils have inherent physical and chemical properties that can make certain uses more or less practical, for example a landowner would not want to build a pond on soil that cannot hold water. To gain a better understanding of these properties, soil scientist use a process called soil mapping to delineate and group similar soils in the landscape for management purposes.

The McMullen County soil survey is being conducted by the Major Land Resource Area (MLRA) 83 Soil Survey project office in Robstown. The soil survey office is staffed by four soil scientists: Clark Harshbarger, Joe Neal, James Akin, and Cody Langston. The MLRA 83 office established in October 2001, recently completed soil surveys in Kenedy, Kleberg, Duval, and Zapata counties. McMullen County will be the final county to have an initial soil survey completed in MLRA 83.

Soil survey provides accurate soil resource data necessary to plan and enhance management of the land for crops, range, recreation, watershed protection, and wildlife habitat. Upon completion of the soil survey, the information will be available free of charge to the public through online resources, such as the Web Soil Survey, http://websoilsurvey.nrcs.usda.gov and at the Soil Survey Data Mart, http://soildatamart.nrcs.usda.gov/. The information will also be available at the McMullen County NRCS office, 204 Elm Street in Tilden, or phone (361) 274-3221 .

Mapping the soil survey of McMullen County has taken soil scientists over the counties unique relief attributed to the Frio and Nueces Rivers, which drain a third of the Rio Grande Plain into the Gulf of Mexico. The soils in McMullen County can range from various sediments, such as heavy black calcareous clay to snow white cemented calcium carbonate. Along the Nueces and Frio Rivers, recent alluvium is deposited annually with the rise and fall of each flood event. The broad floodplain of the Nueces River can reach five miles wide during a 100-year flood event in McMullen County. On some of the oldest landforms, called cuestas or mesas, some of the shallowest soils occur, yet still they support vegetation such as cenizo (Leucophyllum frutescens) and guajillo (Acacia berlandieri) and make excellent habitat for wildlife.

One of the most important items developed in the soil survey report for McMullen County will be the Ecological Site Descriptions (ESD), which provide information on the plant and soil relationships. These are developed and maintained by NRCS rangeland management specialists, who have worked closely with soil scientists over the years to develop a wide range of data, which includes climax vegetation, relative forage quality for livestock and wildlife species and plant species composition.

“It has been a privilege for the soils staff to meet many of the private landowners and to learn about the rich history in McMullen County as well as the county’s many natural resources,” said Harshbarger.

For more information about the McMullen County soil survey, contact the MLRA 83 Project Office at (361) 387-2533 ext. 4.