SOILS y 



of cl.iy. or sandy soil with over 70 per cent, of sand. On the 

 authority of MR. BAMBKK. the Government Chemist, neither marly 

 nor calcareous soils occur in Ceylon. 



Gravelly soil is a term applied to the presence of a consider- 

 able amount of gravel or stones in soils, without reference to their 

 composition ; such soil may partake of the characters of the sandy, 

 clayey, or calcareous classes. 



Vegetable mould. This applies to soils which contain not 

 less than 5 per cent, of humus or vegetable matter ; they may in 

 their turn partake of the character of clayey, loamy, or sandy soils; 

 or they may be composed almost entirely of vegetable matter, as. 

 in the case of peat. 



Peat is a black soil formed by the decay of marsh plants and 

 bog mosses, as Sphagnum. A black plastic peat-like soil occur* 

 on mountain plains in Ceylon at elevations above 5,000 feeU 

 usually forming a Hat barren area, but it in no way forms a 

 substitute for peat. Peat bogs are not adapted for cultivation in 

 their natural condition, although they are the favourite resort of 

 certain plants. Rhododendrons and allied plants thrive best on 

 well-drained peaty soils. To render peat-bogs fertile, the excess 

 of water must be drained off, and lime and sand added. The 

 effect of this treatment is to aerate the soil, destroying the inju- 

 rious acids present, and preventing the stagnation of water. 



Surface soil and sub-soil. These are convenient terms, the 

 former to distinguish the top layer of soil, which is usually 

 distinct by its darker colour (owing to the presence of humus) 

 and looser texture than that underneath, i.e., the sub-soil. The 

 latter, though usually more compact and of a lighter colour, varies 

 considerably in character. It may consist mainly of sand, or of 

 gravel or clay, or even resemble the surface-soil. The surface-soil 

 varies in thickness according to locality and surrounding influences ; 

 in forests and highly cultivated lands it is usually deep, but on 

 steep hill-sides and in dry places it is shallow. 



Heavy and light soils. Although sandy soils are heavier 

 than clay ones, agriculturists and horticulturists call a clay soil 

 "heavy," and a sandy soil "light." These terms, however, refer 

 to the facility with which the soils are worked, and not to their 

 relative weights. 



Cold or warm soils. Clay soils retain much more mois- 

 ture than sandv soils, and this causes a great difference in regard 



