RIGHT USE OF LIME IN SOIL IMPROVEMENT 



stone to meet immediate need. When esti- 

 mating values of such a grade and coarser 

 grades, the amount per acre to be used is a 

 factor. The coarse is unsatisfactory if the 

 price is not low enough to permit an appli- 

 cation sufficient for a considerable term of 

 years, so that it will contain all the fine 

 material needed at once. In that case the 

 coarser material may be expected to meet 

 later need, and may be even more desirable 

 for such purpose, as it would not be subject 

 to leaching. 



Coarse grinding costs much less than fine 

 grinding, and it is the resulting low price 

 that permits the heavy application. As 

 stone varies in hardness and ability of the 

 small particles to withstand disintegrating 

 forces in the soil, an estimate of the differ- 

 ence in price between a 6o-mesh limestone 

 and a lo-mesh one could not serve as a safe 

 guide. The buyer should know the per- 

 centages of a limestone passing through 

 screens of various sizes before he makes a 

 purchase, and should demand part of the 

 saving in cost of production that attends 

 coarse grinding. 



Oyster Shell. Ground oyster shell 

 should be given about the same valuation as 



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