SOUR SOILS 



which is not an isolated one, showed an un- 

 usually rapid loss, but we always expect to 

 find the water from wells and springs in a 

 limestone country strongly impregnated 

 with lime. Drainage waters contain it. 

 The draft by action of water is continuous, 

 and in some types could easily account for 

 sufficient loss to change the nature of the 

 soil. We may place undue emphasis upon 

 this factor, as other causes are at work, but 

 leaching is a leading source of loss. 



Chemical Compounds. A serious cause 

 of lime exhaustion that is being studied by 

 soil chemists is the presence of compounds 

 in the soil that combine with the lime and 

 rob it of ability to serve the soil when new 

 acids form. The practical farmer accepts 

 the statements of the chemists on this point, 

 and probably would not have his interests 

 served by any exact knowledge of the 

 nature of these agents. 



Decaying Vegetation. A cause of acid 

 conditions that is widely known and ac- 

 cepted, and that may therefore stand out in 

 our thinking with undue prominence, is 

 connected with the decay of green vege- 

 table matter in the soil. Many of us have 

 seen fields rendered temporarily unproduc- 



13 



