76 



There are three ways of breaking up the ground 1. Subsoiling or 

 breaking up the soil to the required depth, but leaving the different 

 layers in theirnatural position ; 2. Trenching or breaking up the soil in 

 such a way as to bring the subsoil to the surface and bury the surface 

 soil at the bottom of the trench; 3. Mixing the surface and subsoil to 

 the required depth. This last method necessitates the employment 

 of hand labour, and being, therefore, too expensive for application in 

 Australia, need not be considered here. We have thus to decide 

 between subsoiling and trenching. 



This is one of the vexed questions of viticulture, many persons 

 holding different opinions about it. In the evidence given before the 

 Koyal Commission on Vegetable Products, the majority of witnesses 

 are in favour of subsoiling (see Appendix A), and, in fact, this method 

 is the one which will give the best results in the great majority of cases. 

 In Australia, the most common description of soil is a more or less free 

 surface, resting on a rather stiff subsoil ; in such a case trenching 

 would prove injurious, as by bringing the subsoil to the top the surface 

 would be rendered stiff and difficult to cultivate. It would hinder 

 the absorbtion of water during rain, and by the facility with which it 

 would cake and crack, would promote in an undue manner the 

 evaporation of the necessary moisture during the summer, besides 

 rendering the proper aeration of the soil very difficult. 



Trenching is only to be recommended in the somewhat exceptional 

 case when the subsoil, or at least the soil situated at the depth of a 

 foot or so be looser than the surface soil, or capable of becoming so 

 by exposure to the action of the air. In places where the soil con- 

 tinues identical or practically so to the depth of 3 or 4 feet, it is 

 indifferent which method be employed, although perhaps trenching 

 is to be preferred, as the well-aerated surface soil, being buried whilst 

 fresh layers were exposed to the action of the air, would have a most 

 beneficial effect upon its fertility. 



Partial subsoiling, or only subsoiling a foot or so on each side of 

 the row in which the vines are planted, is not a judicious operation, 

 as it places the roots in a sort of drain, where they are liable to suffer 

 from too much moisture. The advantages to be gained from such a 

 course would in any case be small, as it must be remembered that the 

 roots of the vine spread in every direction, and not only immediately 

 under the plant itself. 



