Soil Survey of Lubbock County, Texas Page: 27
viii, 105 p., [72] fold. p. of plates : ill., maps ; 29 cm.View a full description of this book.
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LUBBOCK COUNTY, TEXAS
Irrigation
Irrigation is important in Lubbock County. In 1974, ap-
proximately 295,000 acres was irrigated. The larger ir-
rigated acreage is in the northern half of the county.
All water used for irrigation is pumped from wells. The
average depth of the wells is about 130 feet. These wells
vary in production, ranging from 20 to 850 gallons per
minute.
Both surface irrigation and sprinkler irrigation are
used. In some places, land leveling or land smoothing is
necessary before a surface irrigation system can be in-
stalled. Row irrigation is the main method of application
on the nearly level clayey and loamy soils. Sprinklers are
used on the gently sloping loamy soils and the nearly
level to gently sloping sandy soils. If a surface system is
used on the gently sloping loamy soils, bench leveling is
needed.
Yields of irrigated crops are two to three times greater
than the yields of nonirrigated crops.
Capability classes and subclasses
Capability classes and subclasses show, in a general
way, the suitability of soils for most kinds of field crops.
The soils are classed according to their limitations when
they are used for field crops, the risk of damage when
they are used, and the way they respond to treatment.
The grouping does not take into account major and
generally expensive landforming that would change slope,
depth, or other characteristics of the soils; does not take
into consideration possible but unlikely major reclamation
projects; and does not apply to horticultural crops or
other crops that require special management. Capability
classification is not a substitute for interpretations
designed to show suitability and limitations of groups of
soils for rangeland or for engineering purposes.
In the capability system, all kinds of soil are grouped at
two levels: capability class and subclass. These levels are
defined in the following paragraphs. A survey area may
not have soils of all classes.
Capability classes, the broadest groups, are designated
by Roman numerals I through VIII. The numerals in-
dicate progressively greater limitations and narrower cho-
ices for practical use. The classes are defined as follows:
Class I soils have few limitations that restrict their use.Class II soils have moderate limitations that reduce the
choice of plants or that require moderate conservation
practices.
Class III soils have severe limitations that reduce the
choice of plants, or that require special conservation prac-
tices, or both.
Class IV soils have very severe limitations that reduce
the choice of plants, or that require very careful manage-
ment, or both.
Class V soils are not likely to erode but have other
limitations, impractical to remove, that limit their use.
Class VI soils have severe limitations that make them
generally unsuitable for cultivation.Class VII soils have very severe limitations that make
them unsuitable for cultivation.
Class VIII soils and landforms have limitations that
nearly preclude their use for commercial crop production.
(None in the county).
Capability subclasses are soil groups within one class;
they are designated by adding a small letter, e, w, s, or c,
to the class numeral, for example, Ile. The letter e shows
that the main limitation is risk of erosion unless close-
growing plant cover is maintained; w shows that water in
or on the soil interferes with plant growth or cultivation
(in some soils the wetness can be partly corrected by ar-
tificial drainage); s shows that the soil is limited mainly
because it is shallow, droughty, or stony; and c, used in
only some parts of the United States, shows that the
chief limitation is climate that is too cold or too dry.
In class I there are no subclasses because the soils of
this class have few limitations. Class V contains only the
subclasses indicated by w, s, or c because the soils in class
V are subject to little or no erosion, though they have
other limitations that restrict their use to pasture, range-
land, wildlife habitat, or recreation.
The acreage of soils in each capability class and sub-
class is indicated in table 3. All soils in the survey area
except those named at a level higher than the series are
included. Some of the soils that are well suited to cul-
tivated crops, for example, soils in capability classes II
and III are now used for urban land. Data in this table
can be used to determine the farming potential of such
soils.
The capability subclass is identified in the description
of each soil map unit in the section "Soil maps for
detailed planning."
Yields per acre
The average yields per acre that can be expected of the
principal crops under a high level of management are
shown in table 4. In any given year, yields may be higher
or lower than those indicated in the table because of
variations in rainfall and other climatic factors. Absence
of an estimated yield indicates that the crop is not suited
to or not commonly grown on the soil or that a given crop
is not commonly irrigated.
The estimated yields were based mainly on the ex-perience and records of farmers, conservationists, and ex-
tension agents. Results of field trials and demonstrations
and available yield data from nearby counties were also
considered.
The yields were estimated assuming that the latest soil
and crop management practices were used. A few far-
mers may be obtaining average yields higher than those
shown in table 4.
The management needed to achieve the indicated yields
of the various crops depends on the kind of soil and the
crop. Such management provides drainage, erosion con-
trol, and protection from flooding; the proper planting
and seeding rates; suitable high-yielding crop varieties;27
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General Soil Map, Lubbock County, Texas (Map)
Map displays soil types along with creeks, towns, schools, churches, power transmission lines, oil and gas pipelines, roads, and railroads. Includes legend and symbols. Scale 1:190,080
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Blackstock, Dan A.; Blakley, Earl R.; Landers, Clifford R.; Koos, William M. & Putnam, Lee A. Soil Survey of Lubbock County, Texas, book, 1979; Washington D.C.. (https://texashistory.unt.edu/ark:/67531/metapth130232/m1/38/: accessed April 26, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting UNT Libraries Government Documents Department.