WSP11679 - Laserfiche WebLink

Home Browse Search

equipment from the Soil "Oons';"vation Service and financial aid from the Farm Security AdministJ'ation and the Agri- cultural Adjustment Administration. All these agencies realized the need for more knowledge of the physical re- sources. Before any soil conservation program could be effective, a c<?mplete inventor;\' of all physical factors was needed m order to establish a sound physical basis on which to formulate such a program. The soil conservation survey, begun in December 1937 and completed in August 1939 and covering both ,the soil conservation districts and the land- 'utilization project, was made to obtain a complete inventory of the khld, de- gree, and extent of erosion; the p,resent land use; the slope; and the soil' type. The survey was recorded on aerial photographs having a scale of approxi- matel;\' 4 inches to the mile. Th,s bulletin deals with the capability of land for agricultural use as shown by the survey. It gives detailedrecom- mendati,ons as to conservation practices on each land-capability class; some aspects of farm and ranch management, and readjustments needed .to establish a permanent agriculture. It I\lso in- cludes a brief discussion of how the districts are working to achieve this goal. Tbe second part deals with the physical resources of the districts, in- cluding descriptions of the area, its climate, and its agriculture, 'and a detailed analysis of the soils,; slope, erosion, and preselit land use data obtained by the soil conservation sur- vey. Maps of the two districts that show the capability of land by colors and the soil types, slope, and erosion classes by sym~ols have been d~plicated on a scale of 2 mches to the mile. One sample map and an index map of the two districts a,ccompany each copy of this bulletin. Farmers or ranchers can obtain additional shcets covering their own lands from their district i super- visors, . Using the Land in Baca County ANY CONSIDERATION of land or its long- time use in Baca Oounty must take 2 into account the climate. Most of the land use problems arise from the fact that rainfall is light, erratic, and Im- certain. Severe droughts of long dura- tion, wide and rapid changes in tem- perature, and high wind velocities are common. Precipitation, evaporation, tempera- ture, and wind velocity vary widely from year to year (pages 35-37). Such variations in Baca Oounty are of great significance to agriculture because they determine the success or failure of crops and to a large extent the activity of soil erosion, An an alysis of the relationship of precipitation to wheat yields froUl 43 places in the High Plains 2 shows that where the annual precipitation ranged between 12 and 13inches only 7 percent of the crops were classed as good, 12 percent poor to fair, and 81 percent failures. Also, 75 percent of the wheat failures occurred in sequences of 4 years or more, 16 percent in sequences of 3 years, and only 9 percent in individual years or 2 successive years. The pic- ture for places having 13 to 15 inches average annual precipitation is not much better; 64 percent of the crops were failures and 40 percent of the failures occurred in sequences of 4 years or more. The average annual rainfall within the county ranges from 13 to 16 inches., The Two Buttes station reports that in 18 out of 45 years, or, over one-third of the time, the annual precipitation was less than 13 inches. In 7 years during this period it was less than 10 inches. There is no doubt that adequate knowl- edge of climate would have forestalled the plowing of many virgin acres here. Agricultural practices have been and still are based ,on above-average rain- fall. The records show that an annual rainfall of less than 15 inches is to be expected about 3 years out of 4. In a region of low rainfall the limiting factor in production of crops usually is soil moisture rather than soil fertility. Most soils in Baca Oounty are poten- tially high in fertility. Even some 2 MATHEWS, 0, R" and BROWN, L. A. WINTER WHEAT AND SOROHUAf PRODUCTION IN THE SOUTHERN GREAT l'r,AINS UNDER LIMITED RAINBALL. U, S, Dept. Agr. Oir, N"o. 477, 60pp" lUus. 1938. Physical Land Conditions in the