BOOT AND TUBER CROPS, ETC. 175 



ered, the soil is left bare to the action of the 

 Feather. When the cottonseed or in equivalent 

 ■mount of cottonseed-meal is returned to the soil as 

 manure, the crop itself does not rapidly exhaust the 

 supply of plant food in the soil. The lint or fibre of 

 cotton contains such a small amount of plant food that 

 many crops may be removed from the soil before it 

 becomes exhausted. Cotton lint is almost pure cel- 

 lulose, and contains very little ash. Three hundred 

 pounds of lint cotton, considered a fair crop to the 

 acre, contain about 1 pound of nitrogen, J pound of 

 phosphoric acid, and 2 J pounds of potash. If the 

 cotton crop removed plant food at this rate it would 

 take a long time to impoverish a soil. But 300 pound b 

 of lint take along with them 650 pound- of leed which 

 contain about 20 pounds of nitrogen, G§ pounds of 

 phosphoric acid, and 7J pounds of potash. The lint 

 and seed together remove from the soil considerable 

 amounts of plant food which must be replaced else the 

 soil will become poor. Cotton lands are much ex] 

 to the weather during the winter months, and it is 

 from this exposure rather than from any demands of 

 the crop that they become exhausted Land should 

 not be cropped continuously in cotton year after year, 

 but several crops should be rotated. 



165. Garden and Fruit Crops. — These crops are of 

 such great variety, and ^r<>w in so many different soils 

 and climates that it would require too much space 

 even to attempt to name the best known varieties of 

 either fruits or vegetables. 



As a rule garden and small fruit crops require warm, 



