APPENDIX I. 



THE METHODS OF SOIL ANALYSIS. 



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How to Take the Sample of Soil. — Owing to the variation in 

 composition of the soil at different depths it is particularly necessary 

 that the sample should always be taken to the same depth and with 

 a tool making a clean vertical cut. Samples taken with a spade are 

 of very doubtful value and do not justify any lengthy examination. 

 A suitable tool consists of a steel tube 2 ins. in diameter and 12 ins. 

 long, with a |-in. slit cut lengthwise and all 

 its edges sharpened fixed on to a vertical 

 steel rod, bent at the end to a ring 2 ins. 

 in diameter, through which passes a stout 

 wooden handle (Fig. 31). A mark is made 

 9 ins. from the bottom so that the boring 

 process can be stopped as soon as this 

 depth is reached. On withdrawing the tool 

 the core of soil is removed by a pointed iron 

 rod. Five or six samples should be taken 

 along lines crossing the field so as to get as 

 representative a sample as possible; the 

 whole bulk must then be sent to the labora- 

 tory. Samples should not be taken from 

 freshly ploughed or recently manured land. 



In very stony soils it is easier to use a 2 -in. auger, but this does 

 not, in our experience, yield as satisfactory a sample as the tool shown 

 here. 



A spud is useful for rapid preliminary inspection of waste land 

 to ensure that the sample is normal ; much disturbance of these soils 

 is sometimes caused by rabbits. 



For precautions to be taken in drawing the sample see Russell, 

 Journ. Bd. of Agric, 1916, 23, 342, and for a discussion of the 

 magnitude of the experimental error see Robinson and Lloyd, Journ, 



347 



Fig. 31. — Tool for taking 

 Soil Samples. 



