30G BOARD OF AGRICULTURE. [Jan. 



the range of plant roots. In an ordinary or true soil there 

 is almost invariably a definite under soil, which is tolerably 

 impervious to moisture, and which retains the soil water 

 near enough to the surface to protect the vegetation from 

 droughts. Generally this subsoil lies at a level below the 

 surface, determined by the penetration of the plant roots. 

 The relative impermeability of this under soil tends to keep 

 the valuable materials of the cultivated layer from penetrating 

 downward beyond the reach of the plant roots. Where the 

 glacial soil is composed largely of clay, as is often the case, 

 the plough tends to form, by its well-known action, a packed 

 laj^er which serves in a measure the functions of a natural 

 under soil ; but in the sandier districts no such compact 

 layer can be formed, and the result is that the fertile material 

 produced by the natural reaction of the plants on the mineral 

 matter contributed to the soil by artificial fertilizing proc- 

 esses, quickly escapes from beyond the plant roots. The 

 only way to meet this evil is by increasing the amount of 

 vegetable matter in the tilled part of the earth. Peat from 

 swamps, sea-weed, green crops ploughed in, all serve in a 

 measure this same end of contributins: to the soil absorbent 

 agents, which may hold the fertile elements as in a sponge 

 until they are availed of by the growing plants. Therefore 

 we may, in a word, sum up the conditions of the treatment 

 which should be applied to the pseudo-soils of our glacial 

 districts as follows : the aim should be to advance the natural 

 process of commingling vegetable matter with the detrital 

 coating as rapidly as possible. 



Considering in a general way the comparative merits of 

 the soils in the glacial districts and those formed under the 

 more general processes which produce the tilled stratum in 

 non-glaciated districts, we observe that glacial soils differ 

 from those of unglaciated districts in the fact that they do not 

 wear out by tillage. In an ordinary soil, derived from the 

 decay of the rocks immediately beneath the surface, the 

 deposits contain within the depth of a foot or so a large store 

 of plant food, which has been slowly accumulated during a 

 great period in the past. This material is rapidly yielded 

 to tillage, producing large crops at the outset, and generally 

 less considerable returns with each succeeding year of culti- 



