2 POMOLOGY 



1. Composition of apple leaves. — The net loss in fertility 

 from orchard lands is somewhat reduced by the return of 

 the leaves to the soil. True, a portion of them is blown 

 from the orchard and hence it would not be entirely accurate 

 to assume that the land received an annual fertilization of 

 the full amount of the leaves produced. Thompson ^ has 

 shown the amount of fertility represented in the fall of 

 leaves for a period of nine years as follows: 



Table II 



"The net loss in soil fertility in growing an orchard to 

 nine years of age is represented by the plant-food retained 

 in the trees at the end of the ninth growing season. This 

 table [given above] is based on the assumption that the 

 leaves have not blown away, but have decayed on the land. 

 The peach trees at nine years of age had reached their 

 maximum size. The apple trees were only about one-fifth 

 to one-eighth their maximum size, but the results indicate 

 that an acre of mature apple trees would take from the soil 

 about the same amount of plant-food as an acre of mature 

 1 Thompson, R. C. Ark. Agr. Exp. Sta. Tech. BuU. 123. 



