This major land resource area (MLRA) occupies 3,950,395 ha (9,754,062
acres) and is located just inland of the southeastern coast of Texas. Much
of this information was obtained from county soil survey reports of this
This land area has a humid subtropical climate characterized by warm
hot summers. Annual precipitation in MLRA 150A is approximately 950 to
1300 mm with about half falling between April and September, which includes
the growing season for most crops. The area is susceptible to hurricanes,
which occur every few years. Snowfall is rare. In approximately 90% of
the winters no snowfall is recorded. On average, less than 10 mm of snow
is recorded. The average relative humidity is about 60% during midday and
approaches 90% at dawn. During the summer months, the sun shines 60% of
the time possible and 60% of the time during the winter months. Winds prevail
from the south-southeast at 15 to 20 km h-1. In the winter months,
the average daily high temperature is 13°C with a low temperature of
7°C. In the summer, the average daily temperature is about 28°C
with an average daily maximum temperature of 33°C. Average annual temperature
is approximately 21°C. The average number of frost-free days is 266
and the average number of growing degree-days ranges from 7000 to 7500.
Geology and Topography
MLRA 150A is located in southeastern Texas just inland from the Gulf
of Mexico and is known as the Gulf Coast Prairies.
Agriculture - The main agricultural enterprises in MLRA 150A are growing
crops, such as rice, grain sorghum, cotton, and raising beef cattle. Some
corn, alfalfa, and vegetable crops are also produced in this area. Farm
income is often supplemented by leasing hunting rights for geese, ducks,
and deer. Livestock operations are mainly cow-calf. On prairie rangeland
and pasture, supplemental feeding is usually needed in winter. Rice has
traditionally been produced by tenant farmers that have short-term leases
from landowners. Rice is commonly grown on a field for two years. Then
the field is fallowed, used as pasture, or used for grain sorghum or soybeans
for one year.
Natural Resources - Soil is a very important resource in this region
for crop production and pasture. Oil, natural gas, and sand and gravel,
are important commercial natural resources. Several underground reservoirs
and rivers, streams, and lakes provide fresh water.
Water is relatively abundant throughout the region. Precipitation is
adequate for crops in most years. In 2 out of 10 years, rainfall from April
to September is less than 500 mm. About 50 thunderstorms occur per year,
mostly during the summer. Additional water is available from underground
sources, lakes, and rivers.
Most of the soils in this area belong to the Gulf Coast Prairies major
land resource area. The dominant soils in this area are the Lake Charles,
Victoria, Edna, Bernard, Midland, Brazoria, Pledger, Orelia, Telferner,
and Dacosta (Table 1). STATSGO soils are
presented in Fig. 1.
The Lake Charles Series consists of deep, very slowly permeable, somewhat
poorly drained clayey soils on uplands. These soils formed in calcareous
clayey sediments. The Victoria series consists of deep, somewhat poorly
drained, very slowly permeable soils that formed in clayey marine sediments.
These soils are on nearly level to gently sloping marine terraces. The
Edna series consists of deep, very slowly permeable, poorly drained loamy
soils on uplands. These soils formed in clayey and loamy sediments. The
Bernard series consists of nearly level, somewhat poorly drained nonsaline
soils. These soils formed in clayey ancient coastal deposits. The Midland
series consists of very deep, poorly drained, very slowly permeable soils
that formed in clayey sediments of late Pleistocene age. These soils are
on terraces and formed under grass vegetation. The Brazoria series consists
of nearly level to gently sloping somewhat poorly drained nonsaline soils.
These soils formed in recent clayey fluvial deposits. The Pledger series
consists of deep, nearly level, somewhat poorly drained nonsaline soils.
These soils formed in recent clayey fluvial deposits. The Orelia series
consists of deep, somewhat poorly drained, very slowly permeable soils
that formed in thick marine sediments on coastal terraces. These soils
are on nearly level to gently sloping uplands. The Telferner series consists
of deep, very slowly permeable, somewhat poorly drained soils on uplands.
These soils formed in clayey and loamy sediments. The Dacosta series consists
of deep, very slowly permeable, somewhat poorly drained loamy soils on
uplands. These soils formed in calcareous clayey sediments. Various physical
properties of these soils are presented in Table
2. Many of these clay soils show a significant temporal change in hydraulic
conductivity depending on the water content of the soil, and may have a
very high initial infiltration rate depending the moisture status of the
soil. Infiltration rates after prolonged dry spells may be 100 to 200 micrometers
per second (Lin et al 1997; Lin et al., 1998).
Lin, H.S., K.J. McInnes, L.P. Wilding, and C.T. Hallmark. 1997. Low
tension water flow in structured soils. Can. J. Soil Sci. 47:649-654.
Lin, H.S., K.J. McInnes, L.P. Wilding, and C.T. Hallmark. 1998. Macroporosity/moisture
effect on infiltration rates in vertisols and vertic intergrades. Soil
USDA, 1998. NRCS, National Cartogrophy & Geospatial Center, Fort