RKI.ATIoV 01 CROP I" H IK lIKMIt VI. Pi;. 'I'l'l; I'l I- Of HIK BOIL. 



Iii con>iderintr the cdccl of the chemical compo^ii ion of the -oil 

 upon the character and magnitude of the crop we have a problem of 

 intricate diflieiilties. If we regard the soil in the light of the total 

 plant food contained therein as indicated by treatment with hot con- 

 centrated hydrochloric acid for a considerable period of time we 

 introduce figures which must he foreign to the problem in question. 

 In point of fact, in order to have any accurate conception of tliU 

 problem it is necessary to ditl'erentiate the amount of any given plant 

 food consumed by a given crop from the total Mipply which is present. 

 This might be illustrated by an attempt to determine how much 

 nourishment would be given a man of average sixe during a da\ by 

 analy/ing the total nourishment in a ban-el of flour from which his 

 day's supply of bread has been made. The actual effect produced 

 upon the man would not be represented by the total amount of flour in 

 the barrel, but only by the total amount of flour he consumed. There- 

 fore, as before .stated, in considering the influence of the composition 

 of the soil upon that of the beet and the magnitude of the crop it is 

 important to know first the total quantity of plant food present, and 

 next to ascertain if possible what portions are immediately available 

 for the use of the crop. The following table has been arranged in order 

 that the interrelations of these factors may be more conveniently 

 observed: 



Ch, mini! tinnfii*,* '//'A-O//.S' (i,,'l ilntii 



!,!'/ tin' o^y/x df fUffOT /<'* yi'nii'ii fh,-fn,,. 



One estimate only. 



' Fi.-l'l No. 



Our studies of this problem are too restricted to justify any con- 

 clusion at present further than to call attention again to the patent 

 fact that the quality of this crop is affected only in a minor degree by 

 the chemical and physical properties of the soil. The case is <|iiite 

 different in respect to the kind of crop best >uited to a given soil and 

 the magnitude of the harvest. These two items are intimately asso- 

 ciated both with the texture of the soil and the quantity of plant food 

 therein. 



