Lime and Calcium Compounds 149 



after plowing and harrowed in, because it works down- 

 ward and naturally leaches into the lower layers of soil. 

 For best results it should be applied at a time when the 

 soil is well filled with organic matter and a crop should be 

 planted soon after its application to utilize the nitrate 

 nitrogen which is a natural result of its action upon the 

 organic matter. 



While it is often most convenient to apply lime in early 

 spring, on most farms, the rotation practiced or the crop 

 will in many cases fix the time of application ; for example, 

 previous to seeding clover or alfalfa. In the case of caustic 

 lime, applications may be made upon plowed ground in 

 fall without injury to seed. When barnyard manure or 

 fertilizer containing nitrogen in the ammonia or organic 

 form are to be applied to the same field with caustic lime, 

 the manure and fertilizer should be well incorporated with 

 the soil and the lime applied after an interval of two 

 weeks or more. 



The form of lime to use. 



It is possible to conceive of conditions under which a 

 specific form of lime should be used to the entire exclu- 

 sion of other forms ; and yet, in general, the form of lime 

 to use depends primarily upon the cost of a pound of 

 actual lime or calcium oxide, and the quantity used should 

 be regulated by conditions of soil, kind of crop and the 

 like. In other words, cost is an important factor. The 

 farmer buying lime should first consider the cost of actual 

 lime in the various forms at his disposal. The cost of a 

 pound of actual lime is easily calculated by multiplying 

 the guaranteed percentage of calcium oxide by twenty 

 and dividing the price of a ton by it. The following table 

 shows this calculation clearly : 



