136 Repoet of Farmers' Institutes 



Definite amounts of the 50-100 mesh separate of Table I were 

 agitated with definite amounts of acid volusia silt loam for 15 

 hours in the laboratory. The reaction between the limestone 

 separate and soil as measured by the decomposition of CaCOs 

 was compared to that found when using the separate finer than 

 200 mesh. The 50-100 mesh material decomposed at the rate of 

 3000 pounds of CaCO., per A. 2,000,000 pounds of soil, while the 

 fined material decomposed at the rate of 6000 pounds per A. 

 2,000,000 of soil. It is evident from these data that, as would be 

 expected, fineness has an extensive influence upon the degTee of 

 solubility. 



However, we must at this point emphasize that no matter 

 whether we use CaO, burnt lime; Ca(OH)o hydrated lime; 

 CaCOs ; or ground limestone ; the consideration of the carbonate 

 must be the basis of comparison, for as we will show, the oxid 

 and hydrate forms are quickly converted again to carbonates, 

 either when they are left on the surface or when incorporated in 

 the soil. Hence, a discussion of the characteristic properties of 

 the three commercial alkaline forms of lime resolves itself into a 

 consideration of the influence of degree of fineness upon the 

 reactive and retentive properties of CaCOs. 



Table II. 



CARBONATION OF BURNT LIME AND HYDRATED LIME UPON AN ACID SOIL. LIME 



APPLIED IN EACH CASE EQUIVALENT TO 28,180 LBS. CaCOs PER ACRE, 



2,000,000 POUNDS OF SOIL. 



CaCOs gain 

 Substance at end of Grand 



applied Treatment eight weeks Average Average 



Burnt lime No rain 19. 282 



Burnt lime No rain 18,426 18,854 



Hydrated lime No rain 19,204 



Hydrated lime No rain 18,432 18,816 



Burnt lime Rain and watered 18,718 



Burnt lime Rain and watered 19,500 19, 109 



Hydrated lime Rain and watered 20,040 



Hydrated lime Rain and watered 18,604 19,322 19,025 



Check - precipitated Car- 

 bonate No rain 19 , 290 



Check - precipitated Car- 

 bonate Rain and watered 20,208 19,749 19,749 



This is made clear by the data of Table II. Treatments have 

 also been made in amounts as small as two tons and as high as 

 one hundred tons, but those of Table II best suit our purpose. 



