ROTATION IN DRY AREAS 399 



plant food or humus removed by the successive crops 

 that are grown; (2) it involves a considerable amount 

 of labor in cultivating so large a proportion of the land 

 each year; (3) it involves the fencing of at least that 

 portion of the land devoted to the growing of pasture. 

 In reply to these objections it may be answered: (1) 

 that the system can be easily so modified as to bring 

 fertility and humus to the land. This can be accom- 

 plished by changing at intervals the portions devoted to 

 the growing of hay and pasture. These may be devoted 

 to the crops of the rotation, and hay and pasture may 

 be grown for a time on the other portion of the land. 

 The ends thus sought will be most completely realized 

 when the hay and pasture plants are of the leguminous 

 order. (3) The fencing to be erected cannot be avoided 

 where live stock are to be kept on the arable farm, what- 

 soever may be the rotation. 



Rotations which include grass crops. As in the pre- 

 ceding rotations, there will be discussed the following 

 under this sub-head: (1) how these may be conducted; 

 (2) the benefits from so conducting them; (3) the area 

 for the same, and (4) the objections to these methods. 



It will be observed that this rotation includes one 

 or more grass crops, of course including the clovers 

 where they may be grown with success and also alfalfa. 

 The various clover crops cannot be grown at their best in 

 semi-arid areas, as already intimated, hence it is not 

 probable that they will ever be given an important place 

 in the rotation in these areas unless under exceptionally 

 favorable conditions. The grass rotation plants will in- 

 clude brome grass, western rye, and, in some places that 

 are exceptionally favored with moisture, timothy and 

 red top. It is almost certain, however, that alfalfa will 

 be grown to a greater extent as the grass crop of the 

 rotation than any other plant. 



