4 BULLETIN 698, V. S. DEPARTMENT OF AGBICULTURE. 



ALTITUDE AND DRAINAGE. 



Most of this district is a high and nearly level table-land with 

 an average altitude of about 4,000 feet and with a rather uniform 

 slope to the east and southeast. The highest elevation reached is 

 about 4,800 feet ia the extreme northwest, while the southeastern 

 border has an altitude of only 1,500 to 2,000 feet. The eastern rim 

 of the high plains is a rough, broken strip where the cap rock is being 

 worn through and erosion is rather rapid. Still farther east, below 

 the cap rook, the surface is rolling. 



Draiaage is eastward through the tributaries of several rivers, 

 among them being, from north to south, the Cimarron, Canadian, 

 Red, Pease, Brazos, and Colorado. In the high plains, above the 

 cap rock, these streams tend to form canyons, the most notable 

 bemg that of the Red River from Canyon, in Randall County, east- 

 ward for about 60 miles. 



SOIL. 



The soUs vary in type from a light sand in some parts to a heavy 

 clay or adobe in others, with clay soils predominating. The sandy 

 soil is covered with bunch grasses, while the heavier soils are covered 

 with a turf of buffalo, blue grama, and curly mesquite grasses. 

 These soils are all quite fertile, to judge from their power to produce 

 crops when there is suihoient moisture. They are, however, deficient 

 in humus because of the scanty growth of the native vegetation. 

 The absence of sufficient humus' in the soil lessens its capacity to 

 absorb and retain the moisture which falls upon it. It also leaves 

 the soil in a condition to become puddled by heavy rains and to 

 bake readUy thereafter. 



CLIMATIC CONDITIONS. 



The United States Weather Bureau has maintained a weather 

 station at AmarOlo, Tex., in the heart of the Panhandle, since 1892. 

 There are disconnected records from two Army posts covering an 

 earlier period. The data herein considered are all from AmarUlo or 

 from the near-by cereal field station. 



The principal climatic, features which influence crop production m 

 the Panhandle are (1) a limited annual precipitation of irregular 

 seasonal distribution, with a great loss of water due to run-off during 

 torrential summer storms; (2) a relatively low atmospheric hu- 

 midity; (3) a high average wind velocity; (4) a wide daily range of 

 temperature, or hot summer days followed by cool nights; and (5) 

 a very high rate of evaporation. 



Precipitation. 



Moisture is the limiting factor in crop production in most of the 

 Panhandle. Precipitation is the primary and most important 

 factor in the moisture problem. 



