FERTILIZERS AND FERTILIZING 1 3 



of using too much, provided the soils are in good 

 condition, the cultivation good and the proportions 

 of the constituents such as to provide an abundance 

 of minerals in available forms." 



LIME OR LIMESTONE 



Lime is applied to the soil mainly to make heavy 

 soils lighter, to make sour soils sweet, to make 

 certain mineral compounds soluble so plants can 

 utilize them, and to act upon the organic matter and 

 make it release plant food. 



As to what form lime shall be applied in, J. C. M. 

 Johnson of Lawrence county, Pennsylvania, writes : 

 *'I am confronted with the problem of applying lime 

 to my soil, either in the form of ground limestone or 

 of burnt lime. I have worked out the solution for 

 the conditions on my own farm, where I can buy 

 burnt lime at an adjoining farm at $2.50 a ton. 

 I must import powdered limestone from Ohio, pay- 

 ing the heavy railroad freight of $1.60 a ton. If I 

 lived near the works in Ohio and could haul the 

 powder to my farm, the case might be different; 

 or, if I lived near the south Illinois penitentiary at 

 Maynard, I could buy powder at 60 cents a ton. 



" The whole question is a chemical one. Its 

 solution depends upon the quantity of the active 

 lime that I would get in a ton. Limestone, or cal- 

 cium carbonate, is composed in the proportion of 

 40 pounds of calcium with 12 of carbon and 48 of 

 oxygen. By burning the stone, 44 pounds of carbon 

 dioxide are driven off. That is, all the carbon and 

 part of the oxygen are forced out by heat. The 56 

 pounds of quick or burnt lime left is called calcium 

 oxide. By adding 18 pounds of water to the 56 

 pounds of burnt lime we get 74 pounds of slaked 



