SUCCESSION IN SOILING CROPS. 235 



covers the states of North and South Dakota and 

 part of Montana and Wyoming, also the Canadian 

 provinces of Assiniboia, Saskatchewan and Alberta. 

 Section No 6 includes the Rocky mountain valleyt 

 north from Salt Lake. It therefore includes thest 

 valleys in Wyoming, Montana, Idaho, Oregon. 

 Washington and British Columbia. Section No. 7. 

 embraces the Rocky mountain valleys south from 

 the latitude of the Great Salt Lake. In other words, 

 it embraces these valleys in the states of Colorado, 

 New Mexico, Arizona, Utah, Nevada and California. 

 Section No. 8 covers the narrow strip of land west 

 of the Cascade mountains and north from Cali- 

 fornia, that is to say, it covers the western parts of 

 Oregon, Washington and British Columbia. 



Succession in Section No. i. In Section No. I 

 the climate is more humid than in areas farther 

 west, and the soil has more of the clay content in it 

 than is usually found in prairie soils. This section 

 therefore has high adaptation for plants of the 

 clover family and for other legumes, as peas and 

 vetches. It has high adaptation also for cereals grown 

 alone or in the mixed form* These crops there- 

 fore should be used to the greatest extent possible 

 in producing soiling food. Corn may be grown 

 for soiling uses in nearly all the tillable portions of 

 this area, and the same is true of rape, millet, fiel<^ 

 roots and cabbage, and in a less degree of sorghum 

 The entire section therefore has much adaptatioi 

 for the growth of soiling foods. 



The succession in which soiling crops may be 

 grown in this section is as follows: Winter rye, 

 alfalfa, medium red clover, mammoth, and alsik* 



