The Bulletin 13 



up as fast as formed. All of the soil nitrogen thus developed from the 

 soil humus is utilized to create more humus, and thus increase the sup- 

 ply in the soil. The action is comparatively slow, and the soil organ- 

 isms, collecting nitrogen from the air at the same time they are extract- 

 ing it from the organic matter of the soil, greatly increase the total 

 supply of soil nitrogen over and above the amount originally contained 

 in the soil humus. The growing crop, thus enabled to use both the free 

 nitrogen of the air and the combined nitrogen of the soil, will, under 

 favorable conditions of agricultural practice, not only maintain but even 

 increase the organic matter content of the soil while producing satisfac- 

 tory yields for the farmer. But not so with burned lime. 



Burned lime attacks the organic matter of the soil just as vigorously 

 as it attacks one's flesh and destroys it by "eating away its substance 

 through chemical action." During this process of chemical destruction 

 of the organic matter, nitrogen is set free just as it is set free when one 

 burns a pound of beefsteak on the stove or burns his corn stalks and 

 cotton stalks in the field. But when caustic lime acts on soil humus 

 it first kills the nitrate-forming organisms and liberates the nitrogen, 

 not in the form of a nonvolatile nitrate, but in the form of ammonia — a 

 gas that escapes from the soil into the air and is lost to the farmer and 

 to his land. Caustic lime burns the organic matter of the soil just as 

 fire burns wood; and as the smoke from the furnace contains nitrogenous 

 gases, so the exhalations from soils treated with caustic lime contain, in 

 a gaseous form, the nitrogen of the rapidly oxidizing humus. 



As this ammonia is escaping upward through a moist soil some of it 

 is held in solution by the soil water and is filially oxidized to a nitrate 

 and used by the plant; but all that fails to be caught in the meshes of 

 the moist soil is, of course, lost, and the land relatively reduced in 

 fertility. It is a common experience that caustic lime gives as good and, 

 in some cases, better immediate results than ground limestone; but the 

 experience is equally common that a large crop by the use of caustic 

 lime this year means a reduced potential fertility and a decreased crop 

 yield the years following. Ground limestone does all the good things 

 burned lime will do, and none of the bad things. 



CITATION OF AUTHORITIES. 



There is an overwhelming amount of experimental evidence to show 

 that unburncd lime is at all times and from every point of view to be 

 preferred to caustic or burned lime for agricultural purposes. Such 

 men as Dr. L. L. Van Slyke of New York, Wheeler of Rhode Island, 

 Hopkins of Illinois, A. D. Hall of England, and a host of other experi- 

 menters and leading thinkers the world over all agree that from a general 

 soil improvement standpoint ground limestone is in every way superior 

 to burned lime. 



