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INSPECTION OF AGRICULTURAL LIME PRODUCTS 

 •^ FOR THE SEASON OF 1931 



MAS: 



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t^Haskins, €)ffi(^al Chemist, assisted by H. R. DeRose. 



— —- .^. , Manufacturers and Brands. 



A ^jt}biifiJ*^9S*nrsev^|^A^iiflis registered for sale in Massachusetts twenty- 

 five brands of 'agricultcr^i^l^i^e an(| one of gypsum or land plaster. The 

 products are grouped as follows: j 



Hydrated or slakecTlime 12 



Ground limestone 13 



25 

 Gypsum 1 



The drawing of samples took place during the months of April, May and 

 June in widely scattered localities in the State by the same sampling agents 

 who drew the official fertilizer samples. Ten per cent of the sacks present 

 were sampled by means of a tube which secured a core the entire length of 

 the package. At least ten bags were sampled provided that number was 

 present. It is believed, therefore, that the analyses which follow fairly 

 represent the lime products which were sold in Massachusetts for agricultural 

 purposes during the year. All of the products registered were analyzed, and 

 it is believed that the list includes all of the lime products that were actually 

 sold for application to the soil, with the exception of some of the local lime 

 by-products such as gas-house lime which are exempt from registration. 



Variations and Deficiencies in the Composition of Lime Products. 



In Table I, devoted to hydrated limes, no serious deficiencies are shown. 

 Two cases were noted where slight deficiencies in calcium oxide occurred. An 

 overrun of magnesium oxide, however, more than made up for the calcium 

 shortage, so that the neutralizing effect of the product was not im.paired and 

 there was no commercial shortage. 



In Table II, devoted to ground limestone, no serious deficiencies are shown. 

 The efficiency of some of the products could be materially improved, however, 

 by finer grinding, as the rapidity with which ground limestone becomes 

 available in the soil depends in a large degree upon the fineness of the product. 

 As illustrating this point, HartwelU, former director of the Rhode Island 

 Experiment Station, found that unsifted ground hmestone (of which 56 per 

 cent was finer and 44 per cent coarser than 80 mesh, 31 per cent was coarser 

 than 40 mesh, and 12 per cent coarser than 20 mesh) was about 80 per cent as 

 effective on mangels and carrots as was slaked lime used in amounts to furnish 

 the same quantity of calcium and magnesium oxides as the limestone. On 

 the other hand, that portion of the same limestone ground to pass an 80-mesh 

 sieve showed an average effectiveness of 102 as compared with hydrated lime 

 at 100. 



Lime Definitions. 



The following definitions of lime products used in agriculture were adopted 

 as official by the Association of Official Agricultural Chemists at their 

 meeting in November, 1931. 



' Circular, Extension News Service, R. I. State College, Vol. 1, No. 6, Nov. 1914. 



