ARID AGRICULTURE. 27 



THE The figures given in our rainfall table have 



BAXKFAXA been carefully selected from Bulletin a Q" of 

 the IT. S. Department of Agriculture. The 

 places at which observations have been taken are 

 representative of the different sections of the 

 arid region. The season when the most moist- 

 ure comes has much effect on the agriculture, es- 

 pecially if dry farming is practiced. As the 

 total amount is given for each season of the year, 

 any one can see at a glance when the most moist- 

 ure falls. On the western slope and in the 

 Great Basin the principal precipitation occurs in 

 the winter months. In northern Montana it is 

 quite evenly distributed through the year. In 

 Colorado, it varies, being generally heavier in 

 the spring months. Attention is called to the 

 fact that on the Divide South of Denver, consid- 

 erable precipitation comes in late summer and 

 the farmers produce good potato crops which re- 

 quire late moisture, without practicing special 

 dry farming methods. The table is especially 

 interesting to the dry farmer and no attempt has 

 been made to show the relation of this rainfall to 

 irrigation further than its general effect on crops 

 in addition to the use of running water and that 

 from storage reservoirs. 



ARID SOILS Three kinds of soil are seldom, if ever, found 



in the arid region. These are peat or muck 

 soils, sour or acid soils and leached out soils. 

 The soils vary greatly, but whether sandy or 



