79(j Journal of the Department of Agriculture. 



DEPARTMENT OF AGH FCITLTURE 



ANALYSIS OF SOILS. 



Methods of Taking Samples. 



In taking; soil for analysis it is of the utmost importance that a truly 

 representative sample be secured, otherwise the analysis will be of little value. 



If the type of soil varies from place to place in a field or farm, separate 

 representative samples of each type should be forwarded for analysis. 



The depth to which a sample is taken is important. In some cases a 

 clear line of separation between the soil proper and the sub-soil is perceptible. 

 This is often shown by difference in colour, the soil being richer in organic 

 matter and therefore darker than the sub-soil. Under such circumstances the 

 sample of soil should be taken down to the line, but in no case to a depth of 

 more than a foot. In all casrs a sample of the sub-soil down to the depth of 

 2 feet must also be sent, separately. 



METHOD OF TAKING SAMPLES. 



Soil samples should be taken in one of the following ways: — 



1. Having selected a representative spot, the vegetation upon it is removed 

 and a hole is dug with a sharp spade to the necessary depth. One side of the 

 bole is then trimmed with the spade so as to be smooth and vertical, the hole 

 lieing cleaned out. A slice of uniform thickness, about 3 or 4 inches, is then 

 lemoved by the spade down to the required depth. This slice is placed on a 

 clean board or sack and mixed ■'-/itli similar slices, oljtained in the same way 

 from other parts of the field. Finally, all the samples are thoroughly mixed 

 together with a trowel or the spade, the sticks, large stones, and roots removed, 

 and a portion of about 9 lb. placed, with a label giving details, in a clean box 

 or suitable bag of canvas, cloth, or other impervious material through whicli 

 the fine soil will not sift out during conveyance to the laboratory, the sample of 

 the sub-soil being kept separate from that of the soil proper. 



2. Another method is to have wooden boxes 6 inches square and 12 inches 

 deep to hold the samples. A large hole is dug with a spade at the selected 

 spot and a square upright lilock of soil is left standing in the centre. This is 

 carefully trimmed with the spade until a box will just fit over it. The box is 

 inverted ovei- the ))lock and forced dowji, the spade slipped under, and the box 

 with its contents removed. A label giving particulars of the soil is put in 

 and the lid screwed on. A sample of the sub-soil beneath should be taken in a 

 similar manner. 



Method (1) will, under ordinary circumstances, I)e found the most con- 

 venient. 



In all cases full details as to exact locality, ett-., must be given on the 

 form provided for the purpose. The average annual rainfall and the altitude 

 should be stated as well. 



BRAK SOUS. 



Should an analysis of a soil be lequired on account of " brak " being 

 suspected, the method of taking the samples is similar to tliat described above, 

 excepting that, provided the soil appears uniform, it should be samjjled in six 

 sections and down to a depth of 3 feet. Should the soil not appear uniform 

 (for example, should hard and soft layers be encountered) the depths to which 

 the various sections of soil are t.iken should be governed by the thickness of 

 the varying layers. 



(Note. — Regulations and tariff governing the analysis of agricultural 

 materials were published in the September, 1920, issue of the Journal, cover 

 pages ii, iii, and iv.) 



