BULLETIN" 836, IT. S. DEPARTMENT OF AGRICULTURE. 



are applicable to a greater or less extent to a large part of the south- 

 ern Great Plains area. 



This bulletin contains (1) a description of the district to which 

 the results apply, (2) a description of the Woodward Field Station 

 and the scope and methods, of the experiments there conducted, and 

 (3) the results obtained. 



DESCRIPTION OF THE DISTRICT. 



The section here described includes the plains of Oklahoma and 

 Kansas, a large portion of Texas, and a small portion of southeast- 

 ern Colorado and of eastern New Mexico. An outline map of this 

 district is shown in figure 1. It includes the main districts producing 



the Dwarf broom- 

 corn crop and a few 

 localities where the 

 Standard variety is 

 grown. It contains 

 at present approxi- 

 mately 300,000 acres 

 of broo m corn, or 

 about 87 per cent of 

 the entire acreage 

 grown in this country. 



TOPOGRAPHY. 



The section just 

 outlined lies between 

 the nine t y-eighth 

 meridian on the east 

 and the one hundred 

 and fourth on the 

 west. It extends 

 north to the northern 

 boundary of Kansas 

 and south to the thirtieth parallel in Texas. In general, it consists of 

 broad rolling plains interrupted for the most part chiefly by the shal- 

 low valleys of the larger rivers. The altitude ranges from approxi- 

 mately 1,000 feet to 4,500 feet above sea level. The average annual 

 rainfall varies considerably in different parts of the district, ranging 

 from about 15 inches in some parts to 30 or more inches in others. 



SOIL. 



The soils of the area are naturally variable. Those of the 

 eastern part have been exposed to greater precipitation and have 



Fig. 1. — Outline map of the southern Great Plains region, 

 showing the principal district producing the Dwarf 

 broom-corn crop. 



