Partnership in Conservation: Yesterday, Today, and Tomorrow.
story by Clark Harshbarger and Gary Harris
The Natural Resource Conservation Service (NRCS) Texas Soil Survey Program recently presented published soil survey manuscripts to three of their partners from the Soil and Water Conservation Districts (SWCD) in south Texas. The soil and water districts were the Agua Poquita SWCD of Duval County, the McMullen County SWCD, and Zapata County SWCD. The surveys were presented as a show of gratitude for assistance that was provided to the soil survey teams during the mapping phase of the project.
Soil and Water Conservation Districts provide leadership in conservation efforts in their respective communities and work hand in hand with the NRCS Texas on locally lead programs that emphasize on the conservation of water and promote soil health. The partnership has been a natural fit for more than half a century.
The SWCD assisted the survey teams by helping them to gain access to private lands in the counties to conduct their work. Some of the rural areas have absentee land owners and in some cases, can be very hard to get in touch with. Permission request letter's written by the soil survey teams were endorsed by the districts and sent to private land owners. But most importantly, the soils team's reputation was passed on by word of mouth at the feed store, court house, and other common places of business within the communities ensuring the benefits of having a high quality natural resource inventory map across the conservation district.
Clark Harshbarger, the MLRA Project Leader with the NRCS Texas soil program traveled to each of the districts to personally thank the boards and to present a published copy of the soil survey manuscripts.
"The manuscripts will forever serve as an historic document and can be preserved for many generations," said Harshbarger.
At the presentation he explained that the soil survey manuscripts are divided into three major sections. The first section provides a forward and general nature of the county, along with general soil map unit descriptions, detailed soil map unit descriptions, as well as taxonomic unit descriptions of each representative soil type found in the county. Within this section it also describes the history, economy, climate, and natural resources within the survey area. It also goes on to explain how the soils are grouped together and where you might typically find them in the landscapes.
The second section provides a snapshot of several interpretive tables that provide in detail potential uses and limitations that are listed by either horizon (layer of soil) or by the soil type. The tables that were published were selected based on common land management practices in the region such as selecting soils for pond reservoir areas, installing plastic water pipelines and fencing post, and chaining, root plowing and disking of the soils to remove or reduce brush. The ratings are based off of inherent soil properties that were sampled, then tested and finally analyzed by the soil scientist to determine representative values. The data was then stored in a national database that is used to deliver the information back to the public.
"There will always be the need to collect more data to keep improving our understanding of soils but at some point we have to make the best decisions possible with the knowledge at hand," said Harshbarger.
He goes on to say, "We now have the benefit of going to Web Soil Survey to access the most current soil data and we encourage all of our users to do so. The published soil survey is a historic reference and the data presented was considered the most current and up to date at the time of its publication."
The last section included in the manuscript is the soil maps. The soils maps are landform based soil boundaries overlaid onto an aerial image. Perhaps this section has undergone the most dramatic change in recent years with the advances in technology such as the use of geographic information systems (GIS) to create soil maps. The historic published manuscripts included maps that were printed to a scale that was deemed suitable for the use and management of the survey area. With modern technology we have the ability to zoom in and out and look at a multitude of thematic interpretations across a given area of interest. One caution that users of the information need to be aware of is that the accuracy can only be assumed at the level of detail that soil survey map was originally intended to be used. Typically this scale was 1:24,000. Which means, that 1 unit on the map is equal to 24,000 units on the ground. Through the use of the internet and GIS, the NRCS can now provide to the public, the most updated scientific information on a yearly basis.
The soil survey maps that have been created over the last 75 years can be incredibly accurate considering the diversity of the climate and geologies that cover across Texas. In recent MLRA update work in south Texas, soil scientist are finding many of the soil materials to be just as the soil scientist before them described them to be. If there is one criticism of the historic work, it would only be that they didn't have the same tools to observe the landforms consistently from one another in some of the younger landscapes that occur on the Rio Grande Plain. With the introduction to Light Detection and Ranging (LiDAR), a remote sensing technique used to collect topographic data, the MLRA office is able to "tighten up" the line work on subtle landforms that are extremely difficult to see when under continuous brush canopy cover. Even with advances in technology the scientist are finding it is imperative to still go to the field to confirm map unit composition and to collect samples to build ranges in data. And when doing so they will depend on their partners from the SWCD to help put the word out that there is a soil scientist coming to a field near you! For more information on how to use or access Web Soil Survey please contact the USDA-NRCS Major Land Resource Office located at 547 South Highway 77, Robstown, TX 78380. http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm.
Larry Miles, Chairman of the McMullen County SWCD (left), is presented with the McMullen County Soil Survey manuscript from Clark Harshbarger, MLRA Project Leader NRCS Texas.
Jose L. Martinez, Chairman of the Agua Poquita SWCD, is presented with the Duval County Soil Survey manuscript from Clark Harshbarger, MLRA Project Leader NRCS Texas.
Jose O. Dodier, chairman of the Zapata County SWCD, is presented the Zapata County soil survey manuscript from Clark Harshbarger.
(Pictured from left to right) Horacio Gonzalez, Jose O. Dodier, Jr., Clark Harshbarger, and Fernando Munoz, Jr.