PLANT GROWTH IN DRY AREAS ill 



all growth in the winter season. If such crops were not 

 grown in these areas, much of the winter precipitation 

 would be lost to crops sown in the spring, hence the wis- 

 dom, as it were, of giving crops sown in the autumn what 

 may be termed the right of way under these conditions. 



When the precipitation is confined mainly to the 

 spring months then spring crops should as a rule be 

 chiefly sown. There will be difficulty in germinating au- 

 tumn crops under the conditions named, and when these 

 do not germinate in the autumn, the results are usually 

 more or less uncertain. While, therefore, it would not 

 be wise under such conditions to try to force the growth 

 of autumn crops, certain spring crops may succeed un- 

 usually well. 



In yet other conditions, the rainfall is variable and 

 more or less fitful. This means that while the bulk of 

 the precipitation falls mainly in the season for ordinary 

 growth, in some instances it does not fall freely at such 

 a time, but may fall later. Under these conditions cer- 

 tain crops would fail outright during the dry period, 

 while others would simply cease to grow for a time, and 

 would again resume and complete growth when the rains 

 come again. Where these conditions are frequent, the 

 growth of such crops should be encouraged. Among 

 these are certain sorghums, and buffalo and some other 

 grasses. They feed not far distant from the surface, and 

 are, therefore, easily accessible to the moisture when it 

 comes. 



At certain times, moisture in the soil, the outcome 

 of precipitation, is more dependable than at other times> 

 though in few instances in dry areas is it absolutely de- 

 pendable. The aim should be to grow plants that will 

 make the bulk of their growth during the most depend- 

 able season for moisture. Thus, when the rain usually 

 ceases to fall for a time after July, as in Montana, early 

 ripening oats are a safer crop than oats that are late 



