How to 

 BUY 



LIMESTONE 



;i.»^?^i?^bK.- 







By ROGER E. GISH, Director 



lAA Soil Conservation Actlvltiaa 



There Is No State Law Requiring The Producers And 

 Sellers Of Limestone To State Quality Of Material But 

 Quarry Tests Are Available At Your Farm Adviser's Office. 



ILAUDE Barlow rested a foot on 

 the fence as he waited for his 

 neighbor, Jim Britt, to drive his 

 tractor on out to the end of the 

 field. "Let 'er cool a minute, Jim, 

 t to ask you something. My al- 

 falfa and clover are not looking so good 

 this year. Do you suppose I need some 

 more limestone?" 



"Well," said Jim, "I've noticed on 

 soil maps that the soil types on your 

 farm and mine are similar, so they 

 would likely require about the same 

 treatment. But I was sure I needed 

 limestone last fall because I had soil 

 tests made to tell me how much I 

 needed." 



"I was talking to Will Haulit," said 

 Claude, "and he said he hauls from the 

 Truckers' Pit Quarry over in the corner 

 of the county. I've heard that the quar- 

 ry price at the Shipping Point Quarry 

 is cheaper but the freight costs to get 

 it here eats you up." 



"It all depends on relative cost on the 

 quality you get." replied Jim. "Lime- 

 stone costing a little bit more might be 

 worth the difference. I understand there 



is a lot of difference in limestone." 



And Jim is absolutely right. There 

 is a lot of difference in limestone sold 

 in the state. When you buy a bag of 

 fertilizer, the analysis is on the bag and 

 the contents are guaranteed by law. 

 There is a lot of difference in fertilizers, 

 as for example, a 4-16-16 is obviously 

 worth much more than a 2-12-6, but 

 at least you are not buying a "pig in a 

 poke" with the analysis in plain sight on 

 the bag. Illinois has no limestone law, 

 and producers and sellers are not re- 

 quired by law to state the quality of the 

 material. 



Among other things, the director of 

 the lAA department of soil conservation 

 activities visits quarries and takes sam- 

 ples of limestone offered to farmers. 

 Sampling is done at the quarry where 

 the material is divided and a portion 

 left for the operator to have check tests 

 made if he desires. Information on 

 calcium carbonate equivalent, fineness 

 of grinding, price, amount produced and 

 location of each quarry is passed on to 

 the farm advisers in the trade area sur- 

 rounding a given quarry. 



There were 94 quarries visited during 

 the last several- months. The calcium 

 carbonate equivalent of material pro- 

 duced varied from 72 to 80 for a few 

 quarries, while several quarries' mate- 

 rial tested 100 or better. Six quarries 

 had a test of 105 per cent calcium car- 

 bonate equivalent. The question often 

 arises as to how a material can test 

 more than 100 per cent. This is possible 

 with a rather pure stone high in mag- , 

 nesiura. 



Magnesium is lighter by weight than 

 calcium but neutralizes as much acid 

 per carbonate unit. Thus, a high mag- 

 nesium stone may test more than 100 

 per cent based on the C.C.E. of a cal- 

 cium limestone. The lower testing ma- 

 terial is suitable for correcting soil 

 acidity. However, it is obvious that 

 material testing 72, for example, would 

 not be as valuable as material testing 

 105 C.C.E. One-half as much again 

 would have to be applied to the soil to 

 obtain the same neutralizing value. The 

 average calcium carbonate equivalent of 

 limestone offered was 93.7. 



Fineness of grinding varies from 62 

 for two quarries to 100 per cent through 

 an eight mesh screen on one quarry 

 visited. The average fineness of grind- 

 ing was 81.6 per cent through an eight 

 mesh screen which has eight openings to 

 the linear inch, or 64 openings per 

 square inch. The requirement for agri- 

 cultural limestone in Illinois is that it 

 have a calcium carbonate equivalent of 

 at least 80 and that at least 80 per cent 

 pass an eight mesh screen to qualify for 

 full PMA payment. 



(Continued on page 30) 



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L A. A. RECORD 



