Fertilizers and Shads-crops 



187 



TABLE V. AMOUNTS OF PLANT-FOOD REMOVED FROM AN ACRE 

 OF APPLE ORCHARD IN TWENTY YEARS 



Total value in wheat, grain, and straw for 20 years, $128.23. 

 Total value in apple, fruit, and leaves for 20 years, $207.45. 



These figures show that an apple crop takes more fer- 

 tility from the land than wheat; and most farmers know 

 from experience that continuous cropping to most farm- 

 crops leads to disaster. The day of reckoning does not 

 come quite so soon, perhaps, with mismanaged orchards, 

 but it is none the less certain. The fact that trees grow 

 to great size and live for many years in forests does not 

 apply to growing apples unless, perchance, they are grown 

 for cider. The quicker the fruit-grower realizes that each 

 crop of fruit makes large inroads on the available supply 

 of plant-food, the quicker will he waken to the fact that 

 scrupulously clean cultivation is not all there is in the 

 handling of orchard land. 



There are thirty-eight elements that may enter into the 

 make up of a plant; ten of this number are considered to 

 be essential to its proper growth. These essential ele- 

 ments are as follows : carbon, hydrogen, oxygen, nitrogen, 

 sulfur, phosphorus, potassium, calcium, magnesium, and 

 iron. Normal development of a plant is impossible if a 

 single one of these elements is absent. Only three of this 



