56 CULTIVATION METHODS AND ROTATIONS FOR GREAT PLAINS. 



alternate cropping and summer tillage without the application of 

 barnyard or green manure must in time deplete the soil of its organic 

 matter and consequently reduce both its drought resistance and its 

 fertility. On the contrary, a properly planned and conducted rota- 

 tion system should maintain or augment the store of organic matter 

 in the soil and thereby increase both its fertility and its drought 

 resistance, and consequently its crop-producing capacity. Such being 

 the case it would be manifestly unreasonable to expect to establish 

 any definite quantitative relations between two such diverging systems 

 until after a lapse of sufficient time to allow the rate of this divergence 

 to become definitely established. 



While the results of these investigations have not yet reached the 

 stage where definite quantitative relations can be established, they 

 have, we believe, produced sufficient evidence to warrant us in making 

 certain recommendations and suggestions for rotations in the Great 

 Plains. 



In the following pages we have attempted to outline certain systems 

 of crop rotation which will combine the best features of the extensive 

 system of farming with the conservation of the organic matter, as 

 well as the moisture of the soil. These rotations, as well as many 

 others, have been on trial at nearly all the stations mentioned and 

 have given sufficiently favorable results to warrant their recommenda- 

 tion for further trials by farmers in the Great Plains area. 



The following tables are intended to represent a quarter section of 

 land divided into as many fields as there are years in the rotation. 

 Of course, this would apply equally as well to a farm of more or less 

 extent than 160 acres, but as a quarter section is the common unit 

 of land measurement in the West we have assumed that each of these 

 rotations is to be practiced upon a single quarter. The letters assigned 

 to the plats indicate the crops to be raised on each plat for as many 

 years as are involved in the particular rotation under consideration. 

 When this cycle has been completed it will be begun over and the 

 same crops will be raised in the same succession continuously as long 

 as the rotation is practiced. 



It is quite important in planning a rotation to devote a great deal 

 of careful thought and attention to the matter, as the best results 

 will obtain where the rotations are carried on uninterruptedly for long 

 periods. It is true that many minor changes may be made in the 

 rotation without seriously interfering with its general plan. We 

 have attempted to point out some of the ways in which the following 

 rotations may be modified to suit local conditions. 



Where annual crops only are used, the beginning of the rotation is 

 a very simple matter. All that is necessary is to divide the farm into 

 as many fields of uniform size as there are years in the rotation and 



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