486 THE HOME, FARM AND BUSINESS CYCLOPEDIA. 



Lime is employed with most effect (1) upon soils which are deficient in 

 it ; (2) upon stiff clays ; (3) upon peaty soils, or those containing a large 

 amount of undecomposed vegetable matter. It does not act energetically 

 upon light soils. Again, on old tillage lands, especially those which have 

 been frequently limed, it exerts but little effect ; while upon newly broken 

 up lands it is highly efficacious. There is a general opinion among prac- 

 tical men that lime should be in a highly caustic condition if applied to 

 old tillage lands. Three, six, and nine tons per acre may be considered 

 respectively to represent light, medium and heavy dressings per acre, and 

 the effect is supposed to last about twelve years. 



Lime is applied in two conditions raw and prepared. When applied 

 as marl or chalk, it may be spoken of as raw or crude ; when subjected to 

 burning or calcining, as prepared. 



Marl has already been defined as a mixture of clay and lime. It no 

 doubt actg beneficially by virtue of both ingredients. Sandy soils have 

 in many cases been greatly improved by the application of " marl " dug 

 from the pits and spread upon the surface. It occurs as blue, gray, red, 

 and yellow marl, of which the first and last are most valuable, and it is 

 applied at the rate of forty to eighty cubic yards per acre. The compo- 

 sition of marls is very various, some containing eight and others eighty 

 to ninety per cent, of lime. They have^been classified, according to 

 composition, into true marls, or those in which calcium carbonate pre- 

 dominates, and clay marls, or those in which clay is the chief constituent. 



Gypsum (calcium sulphate) is another form in. which lime is employed 

 as a manure. It is occasionally applied at the rate of from 200 to 500 

 or more per acre to clover and other leguminous crops. It may also be 

 employed to fix the ammonia in ordinary farm yard manure, by scattering 

 it over the floors of stables and upon manure heaps. Gypsum is an in- 

 separable ingredient of all superphosphates, in which it exists as one of 

 the results of the application of sulphur teroxide to phosphates abounding 

 in lime. A dressing of 500 Ibs. per acre'of a good superphosphate neces- 

 sarily involves the application of about 200 Ibs. of gypsum. 



COMMON SALT (sodium chloride) has long been employed as a man- 

 ure. It may be recommended especially for mangel-wurzel and wheat, 

 and may be applied at the maximum rate of 500 per acre. The effect 

 produced depends much upon the character of the land. Upon stiff and 

 cold soils it is least effective, while upon warmer and dryer soils it is often 

 beneficial. Common salt may be used with good effect upon pastures 

 which carry a coarse herbage, and is useful to mix wibh nitrate of soda as 

 an application for wheat. It checks the disposition of the nitrate to un- 



