United States In cooperation with Department of Texas Agricultural Agriculture Experiment Station Soil Survey of Soil Conservation Webb County, Service Texas ELECTRONIC VERSION This soil survey is an electronic version of the original printed copy, dated October 1985. It has been formatted for electronic delivery. Additional and updated information may be available from the Web Soil Survey. In Web Soil Survey, identify an Area of Interest (AOI) and navigate through the AOI Properties panel to learn what soil data is available. Soil Survey of Webb County, Texas i HOW TO USE THIS SOIL SURVEY Soil Survey of Webb County, Texas ii This soil survey is a publication of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other federal agencies, state agencies including the Agricultural Experiment Stations, and local agencies. The Soil Conservation Service has leadership for the Federal part of the National Cooperative Soil Survey. In line with Department of Agriculture policies, benefits of this program are available to all, regardless of race, color, national origin, sex, religion, marital status, or age. This survey was made cooperatively by the Soil Conservation Service and the Texas Agricultural Experiment Station. It is part of the technical assistance furnished to the Webb Soil and Water Conservation District. Major fieldwork for this soil survey was completed in 1981. Soil names and descriptions were approved in 1982. Unless otherwise indicated, statements in this publication refer to conditions in the survey area in 1981. Soil maps in this survey may be copied without permission. Enlargement of these maps, however, could cause misunderstanding of the detail of mapping. If enlarged, maps do not show small areas of contrasting soils that could have been shown at a larger scale. Cover: Angus cattle grazing an area of Delmita loamy fine sand, 0 to 3 percent slopes. In the background, a gas well is being drilled. Cattle and petroleum products are important resources in Webb County Soil Survey of Webb County, Texas iii Contents Index to map units .............................................................................................. v Summary of tables ............................................................................................ vi Foreword .......................................................................................................... viii General nature of the county .................................................................................1 How this survey was made ....................................................................................4 Soil classification and soil mapping ...................................................................4 Soil variability and map unit composition ...........................................................5 Confidence limits of soil survey information .......................................................6 General soil map units ........................................................................................6 Soil descriptions ................................................................................................7 Detailed soil map units ..................................................................................... 16 Soil descriptions .............................................................................................. 17 Prime farmland .................................................................................................. 44 Use and management of the soils .................................................................... 45 Rangeland ...................................................................................................... 46 Crops and pasture ........................................................................................... 61 Use of the soils for wildlife ............................................................................... 62 Gardening and landscaping ............................................................................. 65 Recreation ...................................................................................................... 65 Engineering ..................................................................................................... 66 Soil properties ................................................................................................... 72 Engineering index properties ........................................................................... 72 Physical and chemical properties .................................................................... 73 Soil and water features .................................................................................... 76 Physical and chemical analyses of selected soils ............................................. 77 Engineering index test data ............................................................................. 78 Classification of the soils ................................................................................. 78 Soil series and their morphology ..................................................................... 79 Aguilares series ............................................................................................. 79 Arroyada series .............................................................................................. 81 Brundage series ............................................................................................. 82 Brystal series ................................................................................................. 84 Catarina series ............................................................................................... 84 Comitas series ............................................................................................... 86 Copita series .................................................................................................. 87 Cuevitas series .............................................................................................. 87 Delfina series ................................................................................................. 88 Delmita series ................................................................................................ 89 Dilley series ................................................................................................... 90 Duval series ................................................................................................... 91 Hebbronville series ......................................................................................... 92 Jimenez series ............................................................................................... 93 Lagloria series ................................................................................................ 94 Laredo series ................................................................................................. 94 Maverick series .............................................................................................. 95 Moglia series .................................................................................................. 96 Montell series ................................................................................................. 97 Nido series ..................................................................................................... 98 Nido Variant ................................................................................................... 98 Nueces series ................................................................................................ 99 Palafox series ................................................................................................ 99 Quemado series ............................................................................................ 100 Soil Survey of Webb County, Texas iv Randado series .............................................................................................. 102 Rio Grande series ........................................................................................... 103 Tela series ...................................................................................................... 103 Verick series ................................................................................................... 104 Viboras series ................................................................................................. 105 Zapata series .................................................................................................. 106 Formation of the soils ...................................................................................... 106 Factors of soil formation .................................................................................. 106 References ....................................................................................................... 112 Glossary ........................................................................................................... 112 Tables Issued October 1985 Soil Survey of Webb County, Texas v Index to Map Units AgB—Aguilares sandy clay loam, 0 to 3 percent slopes ....................................... 17 Ar—Arroyada clay, frequently flooded .................................................................. 18 Bd—Brundage fine sandy loam, occasionally flooded........................................... 19 BrB—Brystal fine sandy loam, 0