14 MAKING HORTICULTURE PAY 



lime, or calcium hydroxide. Thus, ioo pounds of 

 limestone, or 56 of burnt lime, or 74 of slaked lime, 

 contain the same amount of calcium, which is the 

 valuable part in either of the forms of lime men- 

 tioned. 



" Which shall we use on our land — the ground 

 limestone, the burnt lime, or the slaked lime? As 

 each form contains the same valuable element, 

 calcium, the question is evidently one of cost. In 

 order to answer this, we must ask how much 

 ground limestone is equal to 100 pounds of burnt 

 lime. If burnt lime is worth $2.50 a ton, and limestone 

 powder is worth $1.25 a ton at the works, and the 

 freight on the powder $1.60 a ton, how much do I 

 pay for enough limestone to equal one ton of burnt 

 lime? It is easily seen that a ton of limestone 

 powder costs $2.85. 



" Now, how much limestone powder do I have 

 to buy to get the equivalent of one ton of burnt 

 lime? Of course, we must pay 20 times 179 pounds, 

 or 3,580 pounds. This costs $5. Thus, if I apply 

 limestone powder, I pay exactly twice as much for 

 my calcium as when I use burnt lime at $2.50 a ton. 



" From this discussion it is evident that the whole 

 question narrows itself down to the comparative 

 cost of each one of the two forms of lime consid- 

 ered. If a farmer can buy limestone powder for 

 one-half what burnt lime costs, and the hauling 

 distances are about equal, it matters little which 

 he applies. Nevertheless, ease of application should 

 be considered, for it costs much more in time, work, 

 and hauling labor to apply 3,580 pounds than it 

 costs to apply 2,000 pounds. 



" Whoever is interested in lime, soil fertility, or 

 soil renovation should read what leading author- 

 ities say on the subject in various books on soils. 



