226 



SOILS AND FERTILIZERS 



cient in lime, an acid condition may develop to such 

 an extent as to be injurious to vegetation. Nitrogen, 

 phosphoric acid, and potash may all be present in liberal 

 amounts, but in the absence of lime poor results are 

 obtained. Because of the loss by drainage, removal 

 as plant food and the chemical reaction in which it 

 takes a part, there is greater necessity for a liberal 

 supply of active lime compounds in a soil than of any 

 other element of plant food. 



266. Lime liberates Potash. The action of lime 

 upon soils well stocked with potash results in fixation 

 of the lime and liberation of the potash ; the reaction 

 takes place in accord with the well-known exchange of 

 bases explained in the chapter on fixation. The extent 

 to which potash may be liberated by lime depends upon 

 the firmness of chemical combination with which the 

 potash is held in the soil. Boussingault found that 

 when clover was limed there was present in the crop 

 three times as much potash as in a similar crop not 

 limed. His results are as follows : 69 



