SPRING WHEAT IN THE GREAT PLAINS AREA. 3 



' Dealing as it does with only one crop, to which certain sections of 

 the Plains are obviously not adapted, this report does not afford a 

 measure of judging the agricultural value or possibilities for other 

 crops of any section of the country. 



In 1906 the Office of Dry-land Agriculture of the United States 

 Department of Agriculture began field investigations of the problems 

 in methods of crop production in the Great Plains. The work begun 

 at that time has been constantly and steadily added to, until in 1914 

 work was conducted at 20 stations. The results here presented are 

 from 14 stations, records covering only one or two years having been 

 excluded. 



The method of work adopted was that of raising the standard crops 

 of each section both in rotation and by different methods of prepara- 

 tion under systems of continuous cropping. In no case have rotations 

 requiring more than 6 years been used. Those of even this length 

 have been tried only when sod of tame grass crops are included. More 

 of the work has been done with 3-year and 4-year rotations. 



Figure 2 shows a diagram of the plats in the experimental field laid 

 out in 1908 at the Judith Basin Field Station. This station, being 

 a representative one, will serve to illustrate the general scheme and 

 plan of work. The plats here, as in all the work, are one-tenth acre in 

 size. Their dimensions are 2 by 8 rods. Along their larger dimen- 

 sion the plats are separated by bare alleys 4 feet in width. Along the 

 ends of the plats they are separated by roads 20 feet wide. At this 

 station six crops are represented in a series of continuously cropped 

 plats lettered from A to F or G. In this group, plats C and D are 

 alternately cropped and summer tilled, so that each year a crop is 

 grown on land that was summer tilled the previous year and a plat is 

 summer tilled for cropping the next year. 



The remainder of the field is in rotations in which each plat is known 

 by a rotation number and letter. On the field diagram the separa- 

 tion of rotations is indicated by heavy lines. 



The movement of the crops in the rotation is in the direction from 

 Z to A and from A back to the letter that marks the other end of the 

 rotation. 



In figure 2 the diagram is filled out to show the cropping in 1914. 

 The letters following the crop indicate the treatment given the ground 

 in preparation for it, S. P. standing for spring plowed, F. P. for fall 

 plowed, Fal., or S. F., for summer tilled, G. M. for green manured, and 

 D. C. for disked corn land. The addition of the letter M indicates the 

 use of manure. To illustrate: In 1914 plat A of the 4-year rotation 

 No. 14 was in corn on spring-plowed land, plat B was in wheat on 

 disked corn ground, and plat C was in winter rye on fall-plowed land. 

 This would be plowed under for green manure. Plat D was in oats 



