HOCKINGS' GARDEN MANUAL. 



7 



as it is constructed in a very strong manner, with a 

 share but no mould boards, it raises the earth in the 

 bottom of the furrow, and passing under it leaves it in 

 a loosened state without raising it to the surface. 



TRENCHING. 



The result aimed at in this operation is similar to 

 that contemplated by using the subsoil plough, only 

 it is more uniform and effective ; and this is more 

 generally used in forming gardens, orchards, and 

 vineyards. As soils differ much in character, trench- 

 ing has to be modified accordingly: in some cases it 

 may be desirable to bury the top soil six or eight 

 inches for the roots of the trees or vines to grow in, 

 while the next spit would be exposed on the surface 

 to be gradually ameliorated by the sun and atmos- 

 phere ; in other cases, such as the gravelly ridges 

 around Brisbane, which generally have a clay subsoil, 

 and those of a schistose formation, require digging to 

 the full depth and mixing thoroughly ; while a third 

 class, having a rank and unproductive subsoil, requires 

 trenching in such a manner as to leave the bad soil at 

 the bottom. 



Common trenching (which should be two feet to 

 two feet six inches deep) is performed as follows : — 

 On the upper part of the ground to be trenched, 

 mark off' a strip two feet six inches wide, divide the 

 remainder of the ground in a similar manner : dig 

 the whole of the earth out of the first portion to the 

 full depth, and wheel it to the lower part of the ground 

 where the work is to terminate ; dig the top spit of the 

 next space and throw it into the bottom of the newly 

 made trench, and so on until the second space is to the 

 required depth, and thus to the end of the work. 



The method adopted when the subsoil is to be left 

 at the bottom is to remove the strip of surface soil two 



