214 



Journal of Agriculture, Victoria. [10 April, 1919. 



Sometimes tlie surface soil and the subsoil are practically alike in 

 their composition, as in the case of the majority of alluvial soils, but, a> 

 a rule, it will be found that the surface and subsoil differ materially. 

 Often a light sandy loam is found overlying a compact clay subsoil 

 which requires not only stirring with the subsoil plough, but artificial 

 drainage in addition, in order to bring about and maintain its proper 



Plate No. 16. 

 Fig. 1 shows how the ]iar(l])an prevents development of roots. 

 Fig. 2 shows free root development. 



physical condition. Without proper drainage, such a subsoil will, after 

 being stirred, settle down again into its original compact condition. 



The ideal subsoil should be of a fairly open texture, but not too 

 open, for where it is of a loose gravelly or sandy nature, it will usually 

 be found that the surface soil dries out quickly, despite the attention 

 given to it by cultivation, &c. 



