TRENCHING, ROBERTSON ON. $18 TRENCHING, ROBERTSON ON. 



system to double dig, laying up in ridges. 

 Take out an opening two spades broad and 

 two deep, and spread the manure on the 

 surface, digging it into the bottom with the 

 first spit, the last spit going on the top in 

 the form of a ridge. By ridging there is a 

 vast amount more surface exposed to the 

 action of the frost than there would be by 

 level digging ; and in spring, when it is 

 levelled down to get in the crops, it will be 

 found that the frost has torn it asunder and 

 pulverised it so nicely that it goes down 

 like meal, and is in splendid condition for 

 receiving seeds. By adopting a course of 

 trenching and double digging, in a few 

 years the effect will be apparent. A nice 

 depth of rich, easy-worked soil will be 

 secured, which most vegetables will take 

 to and root in readily, and when vegetables 

 do so, whatever the sort may be, we have 

 prospects of a good crop. Where the soil 

 is of a clayey nature, it is a good plan to 

 work in, while trenching and double dig- 

 ging, plenty of leaf mould, old lime rubbish, 

 sand, or anything of a light nature that 

 will help to keep the soil open and sweet." 

 Trenching therefore may be managed in 

 two different ways one in which the rela- 

 tive position of the spits or strata is pre- 

 served, nothing more in change of position 

 of each spit being effected than in turning 

 it upside down, breaking into pieces, as far 

 as may be possible, with the view of 

 admitting air between the pieces, in order 

 to produce further pulverisation ; and the 

 other in which the strata are broken up 

 and thoroughly commingled without any 

 attempt being made to preserve their 

 original position. The first method is the 

 best for garden ground already under culti- 

 vation or in process of renewal ; and the 

 second for ground that is broken up for th'e 

 first time, but even in this case the nature 

 of the soil and subsoil will indicate the 

 kind of trenching that may most profitably 

 be applied to it. 



Trenching is not a process to be carried 

 out every year : it should be carried out in 

 the flower garden at long intervals, as indi- 

 cated, but when it is done, it should be 

 done properly and effectually. The opera- 

 tion of trenching, simple as it appears, is 

 often so indifferently performed as to be of 

 doubtful utility. Sometimes the best soil 

 is thrown into the bottom of the trench, 

 and a foot of sterile clay brought to the 

 surface. Such practice is to be avoided ; 

 for while most soils are improved by a 

 slight admixture of the subsoil, such a 

 mode of procedure as that to which allusion 

 has just been made would prove a quietus 

 to the productive powers of many soils for 

 many years. The process of deepening 

 shallow soils must be gradual. The best 

 mode is to bring up, say, 6 or 8 inches of 

 the subsoil, and mix it with the top soil ; 

 then dig up the bottom of the trench a spit 

 deep, place a layer of manure on the 

 bottom so loosened, and proceed filling 

 up with the next trench, mixing the soil as 

 much as possible, and incorporating the 

 manure with it as the process goes on. 

 The operation is performed by first digging 

 out a trench 3 feet wide and 3 or 4 feet 

 deep, and wheeling the soil taken out to 

 the other end of the ground. Then spread 

 a layer of manure from 9 to 12 inches thick 

 upon the next yard of ground, dig up the 

 bottom of the open trench, divide the yard 

 of ground already manured in the middle^ 

 throw part of the manure from its surface 

 into the bottom of the open trench, and 

 then proceed right down the entire depth 

 with this half trench. Keeping the ground 

 in the half-filled trench at a rough level, 

 proceed to fill up with the 18 inches left; 

 the result will be that the top and bottom 

 earth will not be simply inverted, but will 

 be mixed with manure and thoroughly in- 

 corporated together. The next time the 

 ground is trenched, the bottom spit of sub- 

 soil will be mixed with the other soil, and 



