THE POTATO 23 



kept filled with humus by cover cropping and the 

 use of barnyard manures. 



These experiences show that districts not gen- 

 erally considered capable of growing potatoes 

 like the territory around Denver and some parts of 

 California can be made to produce the crop if 

 proper methods of soil treatment are used. 



The opinions of various authorities as regards 

 potato soils are very interesting*, because each is 

 based on local conditions and experience. While 

 there may seem to be differences of opinion, all 

 really agree on the essentials drainage, aeration, 

 and easily worked, mellow, porous soils. 



Wm. D. Kurd, of the University of Maine, says: 



"In its native state the potato is found growing 

 on high, dry plateaus. One of the first essentials 

 then is a well-drained soil. The kind of soil and 

 proper drainage influence yield, cooking quality, 

 liability to disease, and keeping quality of the 

 tubers. 'Virgin soils' grow potato crops of the 

 finest quality because they are usually free from 

 diseases which affect the crop and have an abun- 

 dance of organic matter and available plant food. 

 The most desirable potato soil is a deep, free, easy 

 working loam. Loams which are inclined to be 

 sandy are usually too poor in plant food and dry 

 out readily, while those inclined to clay may be 

 too hard and apt to retain too much moisture. 

 A proper supply of humus is very important in 

 potato growing. The humus content determines 

 to a great degree the moisture content of the soil. 

 The potato is a crop which uses considerable 

 water in making its growth. Much moisture is, 

 of course, lost by evaporation from the soil, but 

 aside from this it is estimated that a yield of 225 



