382 soils: propeeties and management 



Station. Other fertilizers leaving an acid radicle in the 

 soil also act in this way. It is conceivable that potassium 

 chloride and potassium sulfate might have a tendency 

 to produce an acid condition, but the bases in these salts 

 do not disappear from the soil so quickly as would am- 

 monia, and consequently their action is slower. 



The use of free sulfur on the land as a means of com- 

 bating certain fungous diseases may lead to the formation 

 of a sour soil through the oxidation of the sulfur with 

 formation of sulfuric acid. Lint^ has found that a 

 soil in which sulfur was used at the rate of 600 pounds 

 to the acre for prevention of potato scab, changed in its 

 lime requirement from 2431 pounds to 4177 pounds as a 

 result of the one treatment. 



288. Acidity in relation to climate and to formation of 

 soil. — In an arid or a semiarid climate soils are not likely 

 to become sour. The great source of lime removal, 

 leaching, operates to only a slight extent, or not at all, 

 in a dry climate. The removal of bases in crops is ap- 

 parently offset by the upward movement of bicarbonates 

 in the capillary water. Experience shows that acidity is 

 not a problem in soils of dry countries. 



Soils that are derived from limestone or that have been 

 mixed with limestone soils in the process of their forma- 

 tion are, under similar climatic conditions, less likely 

 to become acid than are soils that originally contained 

 less lime. The fact that a soil is derived from limestone, 

 however, does not insure that it may not be benefited by 

 an application of lime. 



289. Weeds that fllotirish on sour soils. — The acidity 

 or the basicity of soils influences very greatly the growth 



^Lint, H. Clay. The Influence of Sulfur on Soil Acidity. 

 Jour. Indus, and Bng. Chem., Vol 6, pp. 747-748. 1914. 



