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Pit Season Opens in McMullen County

story by Jim Akin, Soil Scientist, Robstown, TX

As hunting season comes to a close in South Texas, the MLRA 83 Soil Survey Office opened 'Pit Season' for the McMullen County Initial Soil Survey on Tuesday, January 26, 2010. The first pit of the season was opened in an area of Cotulla soil by Soil Scientist, Joe Neal using the Bobcat tractor with MLRA Project Leader Clark Harshbarger acting as safety monitor. Soil Scientist Cody Langston, and Jim Akin, Resource Soil Scientist Shanna Dunn, Soil Conservationist Frank Baca of Kingsville, Cartographic Technician Steven Diehl of Temple, and District Conservationist Robert Gibbens also participated in the sampling and describing of the soil pits during the first week of 'Pit Season.' Training in the preparation and description of pits was given to Cody Langston and Frank Baca who are both participating in their first year of Career Intern Program (CIP) with the NRCS.

The detailed description of soils using pits is part of the comprehensive documentation and quality assurance process used by NRCS to ensure complete and accurate soil surveys. "The most important data that we collect from the samples taken from the soil pits are those that provide us the information necessary to deliver to the customer accurate interpretations of the capabilities and limitations of each of the soils. For instance, the samples will be analyzed for particle-size distribution. These relative amounts of sand, silt, and clay will go a long way toward determining how fast water will enter the soil during a rain event. The difference between the amount of water in a soil a couple of days after a rain (field capacity) and the amount of water left in the soil when roots can no longer suck out any more water (permanent wilting point) determines the amount of water available for the plant to use (available water)," said Jim Akin.

A total of 12 soils will be sampled and described in McMullen County, while the soil mapping is being completed this year. In a day, 1 to 2 pits can be opened, sampled, described, and closed. The season is expected to wrap up at the end of February if the land is dry enough to allow access to the sites. The National Soil Survey Laboratory in Lincoln, Nebraska will analyze the samples for physical, chemical, and mineralogical properties of the sampled soils. The interpretations will be reported in the final soil survey report. Those involved in wildlife, cattle, farming and ranching, and land development will find information they need to assist them in making land management decisions.

Soil profile of a Cotulla clay, mapped on 0 to 1 percent slopes in McMullen County, TX.

MLRA 83 Soil Staff members, Joe Neal operating the Texas NRCS Bobcat Tractor to excavate a soil pit and Clark Harshbarger, monitoring safety procedures during the excavation.