The Bulletin 15 



years, 99 bushels more corn, 116 bushels more oats, 13 bushels more 

 wheat, and 51/2 tons more hay than the land treated with caustic lime. 



"Moreover, after these investigations had been in progress for sixteen 

 years soil analysis showed that the caustic lime had destroyed 4^/2 tons 

 of hunms and dissipated 375 pounds of nitrogen per acre as compared 

 with the ground limestone. Thw means that every ton of caustic lime 

 used had destroyed the equivalent of 41/2 tons of farm inanure, and had 

 disdpated soil nitrogen that would cost about $7 to replace in commer- 

 cial form." 



Dr. Frear of the Pennsylvania Station says, in discussing these inves- 

 tigations : "In each case the yields with the carbonate of lime (ground 

 limestone) showed superiority under conditions of this experiment over 

 those following an equivalent application of caustic lime." 



In the same publication, page 8, Dr. Hopkins says: " Half -informed 

 people often advise farmers to use ground limestone or turned lime, 

 depending only upon the relative cost for equivalent quantities; but," 

 says he, "dare we ignore the enormous destruction of humus or organic 

 matter and the dissipation of soil nitrogen as shown by the long con- 

 tinued Pennsylvania experiments, and fully confirmed by the more recent 

 Tennessee experiments? On the contrary, these modem carefully con- 

 ducted chemical investigations as to the effect of caustic lime upon the 

 soil itself forcibly remind us of the long established opinion of European 

 farmers concerning caustic lime, that lime makes the fathers rich, but 

 the sons poor." In other words, caustic lime hums out the organic 

 matter; gives excessive stimulation to the present crop; liberates and 

 destroys the soil nitrogen; and greatly reduces the potential fertility of 

 the land. 



On October 23 we addressed a letter to the experiment stations through- 

 out the United States and its island possessions, asking them which, in 

 their opinion, is better to use, caustic lime or carbonate of lime, in 

 cropping systems where the development and maintenance of a good 

 supply of humus or organic matter is necessary to the production of 

 economic yields. Up to this time 45 stations have replied. Out of the 

 45 that have replied, 32 prefer the ground limestone to caustic lime, 

 6 have no opinion. in the matter, and 7 make no choice between the two 

 forms of lime for agricultural purposes. Four of the stations, Penn- 

 sylvania, Tennessee, and "West Virginia, and Maryland have actually 

 tested the relative value of the two forms of lime for agricultural pur- 

 poses, and these stations are loud in their condemnation of the caustic 

 or burned form. 



The net result, then, of the advice given in extension circular, No. 2Jf, 

 to the farmers of North Carolin-a concerning the use of Caustic Lime on 

 their poor, run-down soils is the constant and systematic reduction of 

 the humus supply of their laiids and the consequent cutting off of the 

 viatural supply of cheap soil nitrates, and the forcing of these farmers 

 into the fertilizer marlcet to huy high-priced ammoniated goods with 



