70 AGRICULTURE OF MAINE. 



Every bushel of apples, potatoes, corn, and grain produced, 

 takes out of the soil nitrogen, phosphoric acid and potash, and 

 unless some return of these is made, the time must come when 

 there must inevitably be a reduction in yield. 



Every ten years. 35 bearing apple trees will take out of an 

 acre of soil, 619 pounds of nitrogen, 140 pounds of phosphoric 

 acid and 716 pounds of potash, and if this is continued over a 

 long period of years, without ploughing in green crops and add- 

 ing some new plant food, soil and trees alike will fail to pro- 

 duce paying crops. 



THE SOIL. 



The apple will grow in a variety of soils. Even on a poor 

 soil it will struggle to maintain its life and to reproduce through 

 its fruit, as reproduction is the real object of all life, animal 

 and vegetable. There are, however, certain kinds of soils that 

 are much better adapted to the development of apple trees than 

 others. A soil that contains a certain amount of clay in its 

 composition is excellent. Trees will grow in a stiff clay, but 

 such soil is often over-saturated with water and trees will not 

 do their best with too much water about their roots. Air which 

 is necessary for the roots of trees and for all plants, is fre- 

 quently shut out by the water in a clay soil. Such soil should 

 be well underdrained, before trees are planted in it. 



A soil that is made up of a mixture of clay and sand, and is 

 known as a clay loam, is excellent for apple trees. 



Trees will grow in a sandy soil, but they will not grow so 

 large, neither will they produce so much fruit. The trees and 

 the fruit on sandy soil are more subject to insect attack, for 

 insects thrive better in a dry soil than in one that holds water 

 for a long time. 



There are, however, variations in sandy soils, that produce 

 not only good trees, but an abundance of excellent and beautiful 

 fruit. 



The subsoil is an important factor in the planting of trees, 

 and its quality and character should be understood. It is closer 

 and more firm than the top soil, and retains moisture longer, 

 but it may be made up of such fine particles of clay, and with 

 so little vegetable matter in it, as to be impervious to water, and 

 this constitutes what is known as hard pan, and if this lies up 

 to within a foot of the top soil, trees will not thrive in it. neither 

 will they produce much or good fruit. 



