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The Use of Lime. 



[OCT 



THE USE OF LIME. 



Lime in its numerous forms has been used for agricultural 

 purposes from time immemorial, and until about forty years ago 

 was much more extensively applied than now. Our pioneer 

 agricultural chemists devoted great attention to this subject, 

 and it is very fully dealt with in early agricultural literature. 



The increased cost of labour, the extensive use of artificial 

 manures — especially basic slag, which contains lime — and the 

 great reduction in the value of corn crops, are the main causes 

 of its greatly lessened use. 



Lime occurs in nature, generally as carbonate of lime, in the 

 form of chalk, limestone, marble, marl, and other substances, 

 and it has been estimated that about one-sixth part of the rocks 

 of the earth's crust consists of this material. 



Lime is an essential part of plant food, and, therefore, soils 

 which are lacking in it cannot produce good crops. It is 

 generally considered that when soils contain less than from "5 

 to I per cent, of lime they are deficient in it. Soils, how- 

 ever, which contain a good deal of organic matter may respond 

 to lime although they possess considerably more than these 

 amounts. 



Lime has not only a direct action as a plant food, but it 

 liberates potash and other alkalis from their insoluble forms in 

 the soil, and thus supplies potash in a suitable condition as 

 plant food. Lime is necessary in the conversion of the inert 

 nitrogen of soils into plant-food nitrogen by the process of 

 nitrification. It has also a marked effect in making heavy soils 

 more friable and less liable to cake, while it greatly assists 

 the natural drainage of these soils. So far as is yet known lime 

 in one form or another is the best remedy for finger-and-toe 

 disease in turnips and swedes, which seems to occur only on 

 soils poor in lime.* 



The most common form in which this material is purchased 

 by farmers is that known as burnt lime, lime-shells, quicklime 

 or caustic lime. This is obtained from limestone or from 

 chalk by burning either in a lime-kiln. Both limestone and 

 chalk, when used for burning to produce agricultural lime of 



* See Board of Agriculture Leaflet, No. 77. 



