18 a EXPERIMENT STATION. [Jan. 



stantly increasing. For this reason, although this matter is 

 somewhat fully discussed in the twenty-first annual report, it 

 seems necessary to refer to it again. There is widespread mis- 

 apprehension as to the value of the chemical analysis of soils. 

 It seems to be very generally believed : — 



1. That chemical analysis will show to what crop a soil is 

 suited. 



2. That such analysis will determine what fertilizer should 

 be applied and the quantities needed. 



It seems also to be generally believed that the cause of crop 

 disease will be revealed by a chemical analysis of the soil in 

 which the crop is growing. 



None of these views is justified by the facts. While the 

 chemical condition of a soil is not altogether without influence 

 in determining the crops to which it is suited, crop adaptation, 

 at least within such range of soil variation as exists in this 

 State, is determined in far greater degree by physical and 

 drainage conditions. Neither does the chemical analysis of the 

 soil show what fertilizers should be applied. Such analysis 

 will determine with exactness the proportion of the several 

 elements present, but it cannot show to what extent these ele- 

 ments are available ; indeed, there is no such thing as a con- 

 stant ratio of availability. The capacity of different crops to 

 extract food from one and the same soil varies widely, and 

 fertilizer requirements are determined in far greater degree 

 by crop than by condition of the soil, within such limits of 

 variation as are usually found in the soils of this State. 



Occasionally a faulty chemical condition is responsible for 

 an abnormal or unhealthy condition of the crop, but in most 

 cases the immediately active cause of plant disease is the pres- 

 ence of a parasitic fungus, and this fungus is usually capable 

 of fixing itself upon the plant, whatever may be the composition 

 of the soil. 



For the reasons briefly stated the chemical analysis of soils 

 does not, as a rule, afford results which have a value commensu- 

 rate with the cost, and this station will not, therefore, make such 

 analysis unless a soil differs widely from the normal in natural 

 characteristics, or has been subjected to unusual treatment of 



