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<br />. 2
<br />
<br />from 18.21 Inches In 1899 to 75.65 Inches In 1957.
<br />Prevailing' winds are southerly to southeasterly during
<br />most months. In January and February northerly winds
<br />prodomlnate. The mean annual relative humidity Is 83
<br />percent at 6 A.M., 56 percent at noon"and 55 percent at
<br />6 P.M.
<br />In winter, temperatures are mild. A low temperature of
<br />32 degrees F or below occurs on about 2 nights out of
<br />3. The dally high fails to exceed 32 degrees on an
<br />average of about 4 days per year. The area experiences
<br />frequent surges of cold continental air In winter. Cold
<br />fronts moving down from the north often are. accompa-
<br />nied by strong gusty winds and sudden drops in tem-
<br />perature; however, cold spells are short, rarely lasting
<br />longer than 48 hours before rapid warming occurs. Pre-
<br />cipitation may fall as rain, freezing rain, sleet, or snow.
<br />In summer, days are warm, particularly In July and
<br />August There Is little variation In the day-to-day weather
<br />during these months. Sunshine is about 75 percent of
<br />the total possible during summer. Refrigerated air condi-
<br />tioning provides the maxlmum comfort Indoors.
<br />Spring and fall are characterized by warm days and
<br />cool nights. Cloudiness and showers are slightly more
<br />frequent In spring than In fall. Also, average w1ndspeed Is
<br />stronger In spring.
<br />The growing season (freeze-free period) averages 228
<br />days. The average dates of the last freeze In the spring
<br />and the first in the fall are March 26 and November g.
<br />About 50 thunderstorms occur each year. A few of these
<br />thunderstorms are accompanied by destructive wind,
<br />hail, or high Intensity rain.
<br />
<br />FarmIng
<br />
<br />Farming Is the leading Industry In Lamar and Delta
<br />Counties. About 77 percent, of Lamar County and 83
<br />percent of Delta County Is suited to cultivation. The aver-
<br />age farm size Is 271 acres In Lamar County and 147
<br />acres In Delta County. In recent years more people have
<br />been purchasing farms to supplement income from In-
<br />dustry.
<br />The main farm enterprises are crops, livestock, dairy-
<br />Ing, and poultry. A few hardwood logs are harvested
<br />each year. The main cash crops are cotton, soybeans,
<br />grain sorghum, corn, wheat, peanuts, and alfalfa. A large
<br />acreage of bermudagrass Is cut for hay.
<br />Livestock operations are primarily cow-calf. Supple-
<br />mental feeding Is generally heavy from December to late
<br />February or March. There are few commercial feedlots In
<br />these counties.
<br />
<br />Natural resources
<br />
<br />5011 Is the most Important natural resource In Lamar
<br />and Delta Counties. Forage for livestock and food, fiber,
<br />and timber for market and home consumption produced
<br />
<br />-----
<br />
<br />SOIL SURVEY
<br />
<br />from the soils of the counties are a major source of
<br />livelihood for many people.
<br />Water Is an Important natural resource. Several lakes
<br />provide high quality water for homes and Industry. Scat-.
<br />tered aquifers throughout the area provide high quality. ,
<br />water for home use.
<br />Wildlife produced on the farms, ranches, and game
<br />management areas provides recreation for many resi-
<br />dents. '
<br />Gravel from high terrace deposits of the Red River
<br />and from the rectified North Sulphur River channel and
<br />chalk and limestone mined from bedrock provide materi-
<br />al for local road construction.
<br />Natural gas Is produced by a few wells In the eastern
<br />part of Delta County.
<br />
<br />How this survey was made
<br />
<br />Soil scientists made this survey to leam what kinds of
<br />soli are In the survey area, where they are, and how they,
<br />can be used. The soli scientists went Into the area know-
<br />ing they likely would locete many solis they already knew
<br />something about and perhaps Identify some they had
<br />never seen before. They observed the steepness, length,
<br />and shape of slopes; the size of streams and the general
<br />pattern of drainage; the kinds of native plants or crops;
<br />the kinds of rock; and many facts about the solis. They.
<br />dug many holes to expose soli profiles. A profile Is the' ,
<br />sequence of natural layers, or horizons, In a soli; It ex-
<br />tends from' the surface down Into the parent material,
<br />which has been changed very little by leaching or by the
<br />action of plant roots.
<br />The soil scientists recorded the characteristics of the
<br />profiles they studied, and they compared those profiles
<br />with others In counties nearby and In places more dis-
<br />tah!. Thus, through correlation, they classified and
<br />named the soils according to nationwide, uniform proce-
<br />dures.
<br />After a guide for classifying and naming the soils was
<br />worked out, the soil scientists drew the boundaries of the
<br />Individual soils on aerial photographs. These photo-
<br />graphs show woodlands, buildings, field borders, roads,
<br />and other details that help In drawing boundaries accu-
<br />rately. The soil map at the back of this publication was
<br />prepared from aerial photographs.
<br />The areas shown on a soil map are called soil map
<br />units. Some map units are made up of one kind of soli,
<br />others are made up of two or more kinds of soil, and a
<br />few have little or no soil material at all. Map units are
<br />discussed In the sections "General soli map for broad
<br />land use planning" and "Soil maps for detailed plan-
<br />ning."
<br />While a soli survey is In progress, samples of solis are
<br />taken as needed for laboratory measurements and for
<br />engineering tests. The soils are field tested, and interpre-
<br />tations of their behavior are modified as necessary
<br />
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