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CHAPTEE V. 

 THE ANALYSIS OF SOILS. 



IN this chapter only a brief outline of the methods of 

 sampling and analysing soil will be given. For full details 

 a treatise on soil analysis should be consulted. The methods 

 described here are such as the author himself uses, and varia- 

 tions may be made in them to suit special cases. 



Sampling. This is an important operation, and careful 

 consideration should be given to it. Much depends upon the 

 particular object for which the analysis is to be made. If it 

 be desired to report upon the soil of a farm or field as a whole, 

 and much difference exists in the soil from different parts of 

 it, care must be taken that in the final sample, each different 

 soil should be represented, as far as possible, by a quantity 

 bearing a proportion to the total sample equal to the pro- 

 portion (of the whole area) covered by that particular soil. 

 Better knowledge of the nature of the soil, however, is ob- 

 tained if samples presenting notable differences be kept apart 

 and analysed separately. 



Then, too, the depth to which the samples are taken is a 

 matter for consideration. Generally speaking, the samples 

 should be taken down to the line of separation of the soil from 

 the subsoil, which is often very clearly visible by a difference 

 in colour, the soil proper being darker (because of organic 

 matter) than the subsoil. The depth is usually from 6 to 

 10 inches. In many cases it is required to also examine the 

 subsoil, when, of course, separate samples must be collected. 



Of the various methods of taking the samples the following 

 may be mentioned : 



(1) Having selected the place, the vegetation growing upon it 

 is removed and a hole is dug with a sharp spade to a 

 depth of about 12 inches, one side (of the hole) being 

 trimmed so as to be quite smooth and perpendicular. 



