CAMPBELL'S SOIL CULTURE MANUAL 130 



vation. In cut No. 20 is shown a hill of potatoes which 

 was grown by shallow cultivation. In this case, it is 

 proper to add, the ground was first plowed eight inches 

 deep, having been previously disked, the plow followed 

 with a sub-surface packer, and the whole portion made 

 thoroughly fine and firm. In securing this illustration, 

 the lateral roots of many different hills were washed out. 

 The main roots running from the stock were almost in- 

 variably found to have traveled in quite a uniform dis- 

 tance from the surface of moisture; the little branches 

 running out from the main roots taking various directions, 

 some lateral and some down. 



The illustration quite perfectly shows all these im- 

 portant facts. Notice the two and a-half inch mulch, and 

 the very fine, uniform condition of the balance of the 

 furrow or plowed portion, where may be seen numerous 

 roots. This represents a hill of potatoes taken from a 

 field grown on our farm in Brown county, South Dakota, 

 in 1894, when thirty-two acres of high, level prairie pro- 

 duced an average of one hundred and forty-two bushels 

 to the acre, and this in a season when almost all the crops 

 throughout the entire semi-arid belt were ruined by the 

 extreme drouth. 



In Cut No. 21, we give another illustration of potatoes 

 grown under other conditions. This .ground was treated 

 practically the same as that shown in cut No. 20, but deep 

 cultivation was applied, and less frequent. The field 

 was cultivated three times, cutting fully four inches deep, 

 which resulted in destroying nearly all the lateral roots, 

 while the other field was cultivated eight times, cutting 

 about two inches. The difference in the result of the 

 two crops was attributed directly to the treatment of the 

 ground after planting. 



