372 



STATE HORTICULTURAL SOCIETY. 



the most advantageous time and place, and nitrification is promoted 

 by the nature of the materials incorporated with the soil at the actual 

 time of tillage. 



This subject of available plant-food, so to speak, is of the first im- 

 portance. It is not enough that the soil is amply supplied with potash, 

 nitrogen, etc., but these elements of fertility must be present in such 

 form as to be readily assimilable to the growing plant itself. This 

 '•availability" is largely a matter of solubility. That is, if the mater- 

 ials are soluble in the soil moisture, they will sooner or latter be 

 brought within the range of soil agencies, which will fit them for the 

 immediate needs of the growing plant. The soil may be exceedingly 

 rich in all the elements of plant nutrition, and still be practically bar- 

 ren. At the Rothamsted Experiment Station in England the fertilzing- 

 value of excessive applications of manure was accurately determined. 

 The results demoustrated the fact that what is called the residual effect 

 of manures is of greatly diminished value — it is unprofitable to manure 

 this year for the crops of succeeding years. 



In considering the fertilizer requirements of orchards, it must be 

 remembered that little or laothing from the harvested crop itself find» 

 its way back to land on which it was grown. The leaves in part are 

 returned to the soil, as well as a part at least of the prunings, but the 

 fruit is removed wholly. It is well known that the twigs and new wood 

 are relatively rich in potash ; the leaves are also very rich in potash,, 

 etc., but every farmer well knows that but little of these find their way 

 back to the orchard soil. Now, as to the fruit : An actual test in an 

 orchard in Pennsylvania shows that one acre of the various fruits given 

 herewith removed from the soil potash, nitrogen and phosphoric acid 

 as follows : 



Nitrogen, 

 Pounds . 



Potash, 

 Pounds. 



Phos. Acid. 

 Pounds. 



Apples , 360 bushels. . . 



Pears, 335 bushels 



Grapes, 8260 pounds . 

 Peaches, 335 bushels 



23 

 16 

 13 



34 

 13 

 22 

 40 



It would not be good judgment to apply precisely the quantities 

 indicated above, with the expectation of obtaining a full crop. The 

 new wood growth and foliage must be accounted for as well as an 

 allowance for losses through fermentation, drainage, etc. It is also 

 impossible to distribute small applications so perfectly as to bring all 

 within the arena of the growing plant. Notwithstanding the fact that 

 the residual effect of manures is economically almost valueless, it will 



