AGRICULTURAL LIME 



79 



Fineness of division of lime (Fippin). 



The finer the Hme (the smaller the particles) the greater its availa- 

 bility. Considering the calcium content, first cost, freight, and fineness, 

 it is often better to use the lump or hydrated or ground lime than the 

 ground limestone or marl; the lump quicklime slakes into very fine 

 particles when applied to the soil. It is impossible to attain the same 

 degree of fineness by grinding that is attained by burning and slaking. 

 Seventy-five per cent, at least, of the ground material should pass a 

 100-mesh screen. The larger the percentage of coarse material, the 

 larger the amount necessary to get the same net effect. Considering 

 composition and fineness as commonly found on the market, 50 lb. of 

 lump hme is equivalent approximately to 



60 lb. hydrated lime. 

 100 lb. air-slaked lime. 

 250 lb. ground limestone or marl. 



Classification of lime for agricultural purposes. 



(1) High Calcium 



Agreement between the Directors of the New England and New Jersey Ex- 

 periment Stations and the Special Committee of the National Lime Manufac- 

 turers' Association of Boston, March 3, 1909. 



(Must contain 93% 

 combined oxides 

 and hydrates and 

 all pass a standard 

 100-mesh sieve. 



(1) Hydrate \ fMust contain not 



less than 90% 

 combined oxides, 

 hydrates, an J car- 

 bonates, of which 

 not over 25% shall 

 be carbonates. 

 Must contain 90% 

 combined oxides 

 and carbonates, of 



^-, ^ which not more 



(2) Caustic \ (2) Fines \ than 10% shall be 

 L (3) Ground carbonates, except 



LIME \ ing Ground, which 



may contain 20% 

 I, carbonates. 



(Must contain 90% 

 combined carbon- 

 ates and pass 50- 

 mesh sieve. 



(2) Land 



(2) Dolomitic 



or 

 High Magnesium 



(3) Ground Limestone 



(4) Kiln Slaked 



(Not guaranteed, 

 contains core, 



ashes, and refuse. 



