Crops. 195 



following manuring per acre is recommended for sugar beets: 

 3 tons of stable manure, 300 pounds of acid-phosphate, 140 

 pounds of sulphate of potash. The soil should be fairly stocked 

 with lime. 



The potato is a surface feeder and must be liberally manured 

 to secure good yields. This crop contains 20 per cent of dry 

 matter, which is mostly starch. It is a staple human food and 

 is also fed to stock. In Europe, one of the principal uses for 

 the potato is for the manufacture of alcohol. Stable manure 

 appears to favor growth of scab and should be applied to a pre- 

 ceding crop. Chloride of potash is also said to be injurious to 

 this crop. The fertilizer recommended per acre is : 225 pounds 

 of sulphate of ammonia, 500 pounds of acid-phosphate and 200 

 pounds of sulphate of potash. 



Fruit crops present peculiar manurial requirements, especially 

 with relation to perennial growths. The composition of the 

 20 per cent of dry matter in common fruits is principally of car- 

 bohydrate nature (invert sugar, sucrose, cellulose, pentosans and 

 pectose) with small amounts of organic acids, ash and nitrogen 

 compounds. Green fruit contains starch, which is converted to 

 sugar in the ripening process. The production of these com- 

 pounds creates special demands for potash. Phosphoric acid 

 and nitrogen are required in smaller amounts, except by the 

 plum, an average crop of which removes 128 pounds of nitrogen 

 per acre. The strawberry, blackberry and similar fruits will 

 produce the best yields when a vigorous cane growth is in- 

 duced by liberal manuring. They thus respond most markedly to 

 applications of liquid manure. The fruit of trees draws its nu- 

 trients from an extensive woody growth and volume of sap, but 

 these sources must be reinforced to keep the trees in vigorous 

 bearing condition. Light yearly applications of farm manure 

 or complete fertilizers are recommended for these crops. 



Forest growth presents practically the same demands on fer- 

 tility as do fruit trees, but as has been pointed out, this demand 



