148 



THE PLANTBli's GUIDE. 



new earth brouglit up be properly pulverised, and manured 

 with compost. Besides, from poor clays, and lands in- 

 clined to moisture, it will banish Rushes effectually, (if 

 Rushes be produced by surface causes,) — one of the most 

 troublesome weeds which we have to eradicate. It is 

 unnecessary to pursue the subject further in this place, 

 although it has hitherto attracted no general notice. But 

 as it rises greatly in the scale of interest and consequence 

 from its importance to both husbandry and arboriculture, 

 it may be worth while to give the details and explanations 

 in a note below, to which I refer the inquisitive reader.'" 



In trenching entire spaces or areas for groups, more- 

 over, two important savings are made in the execution of 

 the work. First, in the trenching itself — as not more 

 than eighteen inches are necessary for the deepening a 

 light soil, and for one that is heavy not more than twenty 

 inches. This saving obviously results from the far greater 

 and more uniform scope that is given for the elongation 

 of the roots, on a space of ground of such increased mag- 

 nitude. The second saving is, that on such a space it is 

 very seldom that any extra earth can be wanted, in order 

 to supply a deficiency of soil, as must sometimes happen 

 with single trees. On clayey land you may freely go 

 down, and procure the depth required ; because no water 

 can stagnate where there is no pit to hold it, but where 

 the entire bottom of the space or area trenched is worked 

 to a uniform level, that is, a slope-level, so as to carry off 

 the water collected from the surface ; and hence the great 

 excellence of deep trenching in every case. The only 

 case which can require an aid of extra earth to the soil 

 is where pure sand or gravel, as on small eminences, rises 

 nearly to the surface, and where there is next to nothing 

 to form the nourishment of plants. ^ 



* Note V. 



