3S1 



THE FARMER'S MAGAZINE. 



its reach, and it had been very fancifully conjectured 

 that marl may retain some of the qualities which 

 its constituent substances acquired as rocks by the 

 igneous agency of their production. Such con- 

 jectures are amusing, but add nothing to the 

 science, or the systematical experience of the prac- 

 tice of any art or use of a materia]. 



For the sake of conciseness, marls may be 

 divided into two kinds — shelly and earthy. Minute 

 accuracy will make many subdivisions, but these 

 two divisions will mark the distinction of having 

 more earths or lime in the constitution of the sub- 

 stance. Shell marl is generally found under masses 

 and at the bottom of lakes, soft, and of a bluish 

 white colour, and seems to be a natural deposit 

 where water has been stagnant. The composition 

 usually partakes of the nature of the surrounding 

 earths, and may properly be considered as a com- 

 post of organic matters with earths and calcareous 

 materials reduced without the action of fire. It 

 often occurs in ponds and land-locked bogs, on 

 the sides of hills, and on the banks of rivers, 

 formed by the accumulation and decomposition of 

 small shells, as whelks and periwinkles, and also of 

 bivalves ; and lying in beds of different thickness, 

 running horizontally, but seldom of great extent. 

 It has been found to contain 84 per cent, of pure 

 lime. 



Clayey marls are found below mosses and in low 

 wet places, at the foot of hills, and in the valleys 

 between them. The composition and the quality 

 vary much, from 15 to 40 per cent, of calcareous 

 matter, and the remainder of clay and sand, with 

 mixtures of sand, loam, clay, and chalk, according 

 to the nature of the animal, vegetable, and earthy 

 matters which abound in the locality, and which 

 have been collected and decomposed together. 

 Separate and distinct beds of clayey and sandy 

 rnarls have been found alternating with clays and 

 limestone, of which clay is the undermost stratum, 

 the marl being of very different colours, as it has 

 been exposed to the elements composing and sur- 

 rounding it, the redness showing the presence of 

 iron, whiteness that of calx, the blue and yellow 

 showing the clayey composition mixed with other 

 substances. It is sometimes found very hard to 

 dig, with lumps of chalk and limestone in it, lying 

 under stiff claj's and low black grounds, and very 

 compact and greasy; sometimes flaky, smooth, 

 and red in colour, crumbling, and of very good 

 quality. Other kinds are slatj', and of the shape 

 of flags, and of a bluish colour, are easily dis- 

 solved by the action of rains and frosts, and are of 

 good quality. 



Marls are v/ell suited to be used as a manure in 

 top-dressing lands, as the substance crumbles by 

 exposure, and the particles are most minutely sub- 

 divided. The most preferable application consists 

 m laying it on a grass ley in the end of the autumn, 

 or in the early winter, when the herbage will be of 

 little value, and when the changes of the weather 

 %yill effect the decomposition of the marl, by the 

 time the grass shoots in the spring. It will thus 

 secure the regular spreading over the surface, and 

 the bush-harrow and the roll being afterwards em- 

 ployed, the particles will be well reduced and 

 pressed mto the soil. The crop of grass will be 



greatly improved, and when the land is ploughed 

 for a grain crop in the following season, the marl 

 will be thoroughly matted in the turf, and the 

 vegetable sward which it has raised will most ma- 

 terially promote, l)y its decomposition, the subse- 

 quent fertility of the land. This mode affords 

 time for the crumbling of the marl, and it raises 

 a close vegetable growth on which the future crops 

 depend for their nutriment. The substance that 

 is used as top-dressing cannot be incorporated 

 with the soil from want of arable culture, and con- 

 sequently the efi'ects depend on the influence which 

 it is able to exert on the materials with which it 

 comes into contact. By raising a ^arge quantity 

 of grassy herbage, in the shape of roots, leaves, 

 and culms, it afl^ords by the decomposition of these 

 substances, wlftn the land is ploughed, a vegetable 

 *' pabulum " to the growing crop, with which no 

 manure yet known is superior, if any one be equal 

 to it, either in action or duration. Consequently, 

 all top-dressings of an earthy nature should be 

 used with the view of producing this vegetable 

 growth for the support of the future crops. The 

 quantity of marls used in this way on grass land 

 may be stated at an average of 40 to 60 cart loads 

 of two horses. 



The use of marls on the fallows of barley and 

 turnips in the spring, admits of the better mixing 

 with the soil, provided the suitable reduction of 

 the marl can be accomplished, which may be done 

 by exposure if the v/eather be favourable, before 

 the last ploughing of the land, and when the na- 

 ture of the marl itself favours the r'i-isolution. It 

 is often necessary to go over tlic work, and brcLk 

 the land with hand-mallets. The weather is the 

 best operator, and the time of exposui'e may pro- 

 duce some reciprocal actions. In whatever manner 

 marls are apphed, it is most absolutely necessary 

 that the substance be reduced as fine as possible 

 by breaking the lumps, spreading it evenly, by har- 

 rowing and rolling when dried after rains, and by 

 being ploughed into the ground by means of a 

 shallow furrow. Some marls will crumble to pow- 

 der immediately on exposure, or very soon after ; 

 others require the changes of both winter and 

 summer, and also much attention in improving the 

 action of the weather, by breaking, harrowing; and 

 rolling. 



The effects of marls have been much the great- 

 est on dry heathy grounds that have been con- 

 verted into arable cultivation; and on sandy loams, 

 and on all sandy land generally, the applications 

 have been very beneficial. On raw, damp loams, 

 reports are less favourable : the marl attracts 

 moisture, and thus increases the poachy looseness 

 of the land. Clays are much improved by large 

 quantities of marl, but the clay must be pulverized 

 in order to facilitate the incorporation with the 

 marly substance. Practice directs the use of 

 clayey marls on all light soils, and the apphcation 

 of sandy and shell marls to heavier lands ; but all 

 these substances have been found useful on any 

 soils, when judiciously employed. 



Marls are often made into composts with earths 

 and farm-yard dung, either in layers in the heaps, 

 or in the bottoms of the fold-yards, where they will 

 be soaked by the urinary juices, and afterwards 



