Ififi MXETERNTH REPORT. 



as 271. In this case there was more K and P^O- than required. The 

 same may be said of Mg and S. However, this soil needs more lime. 

 In this particular experiment the total concentration was quite high. 

 When this was lowered to about 2 atmospheres the same concentration 

 as that of the poor soil solution the ratio of salts was 163. This showed 

 that the soil needed liming also and had more K and P ,04 than required. 

 The original soil has been treated with Ca(NO,)^, and planted with 

 wlieat. This work still awaits completion. 



The study outlined above has so far shown that with soil solutions as 

 well as with distilled water cultures there is an optimum or best pro- 

 portion of salts in which the test plants grow better than in any other. 

 It also shows as especially indicated in case of the good soil solution 

 that at different concentrations the optimum ratio of salts differs. It is 

 further believed that by this method of study we can get an indication 

 of the needs of the soil and so finally obtain a clearer understanding of 

 the soil fertilization recjuirements. It would seem quite feasible to 

 devise a rational system of fertilization from tlie standjioint of balanced 

 solutions. 



Department of Hotany, Michigan Agricultural C'ollege. 



