Summary Conclusions. 223 
and a little more of that as he thinks the different 
trees or the different types of land may need. 
There is no other way of arriving at this local 
knowledge except by trying for oneself. If one is 
observant of the conditions, he will after a time come 
to have an intuitive sense of what the land prob- 
ably needs, but he may not be able to tell just 
why it needs it. In most matters of handicraft in 
agriculture, the skilled man develops methods and 
results almost unconsciously. These methods are 
really founded upon close observation and truthful 
inductions, but the person can rarely ever impart 
this particular information to his neighbor. The 
only general statement, perhaps, which can be made, 
is that liberal applications of potash and_ phos- 
phoric acid should nearly always be made to bearing 
fruit plants, if the grower desires the best results; 
and he may be able to supply his nitrogen more 
cheaply by cover crops and tillage than by buying 
chemicals, 
