B. P. I.— 585. 



A STUDY OF CULTIVATION METHODS AND CROP 

 ROTATIONS FOR THE GREAT PLAINS AREA. 



INTRODUCTION. 



The Office of Dry-Land Agriculture Investigations of the Bureau 

 of Plant Industry has been carrying on investigations in dry-land 

 agriculture in the Great Plains area since the spring of 1906. A 

 large amount of data has accumulated. Urgent demands are being 

 made by settlers, actual and prospective, for information concerning 

 the best methods of farming in the Great Plains. It therefore seems 

 desirable at this time to give publicity to such of these facts and figures 

 as have a direct bearing upon this subject. It is not claimed that 

 sufficient data have yet been accumulated to form the basis for final 

 conclusions. It is believed, however, that these results are of suffi- 

 cient importance to deserve careful consideration and that they 

 throw some strong light upon the much controverted questions of 

 summer tillage, continuous cropping, and crop rotation. It is hoped 

 that the tentative conclusions drawn and the suggestions made may 

 be useful. 



QUESTIONS ASKED. 



These investigations were undertaken to answer the following main 

 questions, besides many subsidiary ones : 



(1) How can the largest average yields of four staple crops — corn, spring wheat, 

 oats, and barley — through a long series of years be obtained: (a) By raising the same 

 crop continuously by ordinary methods of culture now in practice; (6) by continuous 

 cropping with the same crop, using the most approved methods of cultivation for 

 moisture conservation; or (c) by alternate cropping and summer tillage by the most 

 approved methods? 



(2) Do moisture conservation methods pay where continuous cropping to the same 

 crop is practiced? 



(3) Do alternate cropping and summer tillage pay where the same crop is raised 

 each alternate year? 



(4) How do simple 3-year crop rotations compare with continuous cropping, both 

 with, and without conservation methods, and with alternate cropping and summer 

 tillage in the profitable production of crops? 



(5) What 3-year rotation has given the best results? 



(6) Which gives the best results, fall plowing or spring plowing? 



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