LIME 141 



fication, while sodium nitrate depressed it; both potassium sulphate 

 and calcium carbonate accelerated nitrification in soil. Brown, 

 working with a typical Wisconsin drift soil, found that the applica- 

 tion of ground lime up to 3 tons an acre increased the number of 

 bacteria in the soil, and also the ammonifying, nitrifying, and nitro- 

 gen-fixing powers of the soil. The increase was in every case nearly 

 proportional to the limestone applied. 



At times the increase noted in ammonification is due to the 

 retention of the volatile ammonia by the carbonate, as is shown by 

 Lemmermann's results where the addition of calcium carbonate to a 

 soil up to 1 per cent, reduced the volatilization of ammonia, but 

 calcium oxid had the opposite effect. Both calcium chlorid and 

 calcium sulfate reduced the loss of ammonia, but the chlorid was 

 the only salt of magnesium tested which had this effect. Potassium 

 and sodium chlorids, sulphates, and carbonates all reduced the 

 absorptive powers of the soil. Paterson studied the influence of a 

 number of substances upon nitrification with the result that caustic 

 lime was found practically to stop all nitrification. Calcium car- 

 bonate promoted it, as did also magnesium carbonate; gypsum was 

 less effective, while ferric hydrate had a decidedly favorable effect. 

 Sodium chlorid, on the other hand, had a distinctly injurious effect. 



Kelley studied the effect of calcium and magnesium carbonate 

 alone and in combination upon ammonification and nitrification. 

 In his work calcium carbonate only slightly stimulated ammonifi- 

 cation of dried blood, but it had a marked stimulating effect upon 

 nitrification. The magnesium carbonate was found to be toxic 

 to both groups of organisms. No antagonism was found to exist 

 between calcium and magnesium. Later, when working with 

 Hawaiian soils, he reports a stimulation for both. The results, 

 however, varied with different soils, and he considers the lime- 

 magnesia ratio of little importance as regards the ammonifying 

 and nitrifying organisms. Allen's conclusion is that large quantities 

 of limestone must be applied to a non-calcareous soil in order to 

 bring its nitrifying powers up to those of natural calcareous soils. 



Lime. Peterson and Wollny found that lime increased the carbon 

 dioxid given off by soils, and Ebermayer, Hilgard, and Hartwell 

 and Kellogg proved conclusively that lime increases the decay taking 

 place in a soil. 



Chester showed that lime increased the number of bacteria in 

 soil, the increase being proportional to the lime applied up to 4000 

 pounds an acre. He considered the effect as being due to the lime 

 giving to the soil a more favorable reaction for the growth of bac- 

 teria and not to its direct action upon the organisms themselves. 



Lime not only increases the number of organisms in a soil, but 

 it increases the ammonifying powers of the soil, as is seen from the 

 work of Kemy, Ehrenberg, Vorhees, and Lipman, 



