CERTAIN ELEMENTS IN NURSERY PRACTICE 175 



The land should be strong enough to raise a good crop of wheat 

 or corn. 



With fruit-trees, the age of the tree determines its salable- 

 ness; therefore it is imperative that the growth within the 

 given time be rapid and strong. With ornamentals, however, 

 the value is determined by the size of the specimen, with little 

 reference to its age. It therefore follows that lands not suf- 

 ficiently strong to allow of the profitable growing of fruit-trees 

 may still be useful for growing ornamentals. 



In considering the question of the fertility of nursery lands, 

 it is first necessary to determine what are the proportions of 

 the chief elements of plant-food removed by the trees from 

 the soil. The standard investigations of Roberts, at Cornell, 

 still constitute an excellent record : 



"Amounts and values of fertilizing constituents removed 

 by an acre of nursery trees in three years : 



"The above results show conclusively that but a small 

 amount of plant-food is removed from the soil by the growth 

 of nursery stock. They also show that more phosphoric acid 

 is removed by the apples and pears than by the peaches and 

 plums ; but any ordinary soil, cultivated as nursery lands are, 

 should easily furnish in three years ten times the plant-food 

 used by the trees. In order to compare the drafts made by 

 nursery stock and some of the common crops raised in mixed 



