108 FERTILIZERS 



should be applied after growth has started so that it may be 

 taken up quickly. 



The fertilizing of the various kinds of fruit trees will vary 

 somewhat, but there will probably not be any greater variation 

 that might occur between two different varieties of the same kind 

 of fruit or between two blocks of the same fruit on different 

 soils. For example, the Wag-ener and Gravenstein apples will 

 probably vary nearly as much in the fertilizer requirements as 

 Avill the general classes of apples and peaches. And two blocks 

 of Baldwin apple trees on very different soils may need quite 

 as different fertilizers as a block of peaches and a block 

 of apples. 



There is much recent experimental data to show that in the 

 application of nitrogen it is desirable to get the fertilizer on the 

 orchard early in the season. In general the data when the buds 

 are beginning to swell seems to be about the right period for 

 this application. 



QUESTIONS 



1. Compare oi-chards with wheat in their exhaustion of soil fertility. 



2. What have experiments proved in regard to orchard fertilizers? 



3. What are the effects of nitrogenous fertilizers? 



4. Give the effects of fertilizers rich in potash. 



5. What is the influence of phosphoric acid on fruit trees? 



6. Discuss the forms of fertilizer to be used in supplying nitrogen. 



7. From what sources maj' the phosphoric acid be derived? Which are 



best for young trees? 



8. What two forms of potash are in common use? Give an advantage 



of each. 



9. Is orchard fertilizing practised in your section? 



