REPORT OF THE CHEMIST. 



161 



MARL. 



This naturally-occurring source of lime might be used with advantage and profit on 

 many Canadian farms, since many of our soils require lime ; and, where readily obtain- 

 ed, marl is the cheapest of all lime fertilizers. 



It is chiefly in connection with the muck beds already referred to, that deposits, 

 of marl are found. Thus it happens that two substances, the natural complements of 

 each other, supplying the necessary plant food for light and sandy soils in the cheapest 

 forms obtainable, often occur together and in proximity to those lands that would be 

 most benefited by their application. 



Marl is essentially carbonate of lime, the poorer samples containing more or less 

 clay and iuert matter. It forms a grayish white mass and frequently incloses many 

 small shells, when it is known as shell marl. 



Previous reports have given the composition of marls found in Ontario, Quebec and 

 the Maritime Provinces ; we now present the analyses of five samples sent from the 

 vicinity of Okanagan Mission, British Columbia. 



Analyses of Marls from British Columbia. 



These samples, although showing a very high percentage of carbonate of lime, are 

 not in the best physical condition for disintegration and solution in the soil, being hard 

 and rock-like. They ax-e known as " indurated " marl. If, however, they were finely 

 crushed, their application would undoubtedly be of great benefit to lands deficient in 

 lime. 



USES OF MARLS. 



Lime is a necessary constituent of plant food, and consequently every fertile soil 

 must contain this material. Marl may be used to furnish cheaply and effectively lime 

 to soils lacking in this constituent. 



Potash is another essential in the composition of plants. The lime in a soil serves 

 to set free the potash from its insoluble forms, so that in the presence of lime or marl 

 soils containing only a minimum of immediately available potash, may produce luxuriant 

 crops. 



Lime promotes nitrification of the organic matter (humus) of a soil. The nitrogen 

 of humus is not in a condition assimilable by plants, but must first be converted into 

 soluble nitrates. This is brought about by the agency of bacteria, and their develop- 

 ment is fostered by the presence of lime in the soil. For this reason, lime or marl gives 

 increased fertility to many soils rich in humus and otherwise of excellent composition. 

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