234 AGRICULTURAL REPORT. [If 459, 460 1 , 460 2 



They ought to be scattered broadcast, as a general improvement of the land, not 

 in the drill ; and whenever practicable, they ought be to used in conjunction with 

 vegetable matter. 



The very precept of broadcast scattering, necessarily involves the condition, 

 that the material should be in a certain state of comminution ; not in blocks or 

 lumps, such as it may form immediately after digging from the pit. In most 

 cases, exposure to a few rains with dry spells intervening, will cause the 

 material to crumble sufficiently for all purposes. It is only the white marls of 

 the Tertiary, which sometimes resist this treatment, and require to be pounded — 

 which is rarely, however, an operation of any difficulty. Generally, the marl 

 may be hauled to the field as it comes from the pit ; being thiown from the 

 carts in small piles, it will be in a favorable condition to be acted on by the 

 weather, especially in winter ; it may then be scattered, and turned under by 

 the first plowing, in spring. 



459. With most of the bluish marls, this preliminary exposure becomes a 

 matter of great importance, and olten of necessity, on account of their fre- 

 quently containing small amounts of iron pyrites. This mineral, by the action 

 of the atmosphere, is transformed into green vitriol or copperas (11258), and as 

 such, would, for the time being, prove highly noxious to plants — causing ''dead 

 spots" wherever a crystal or lump of the mineral thus decays. In the presence 

 of a plentiful supply of lime (with due access of air), however, the copperas 

 would be rapidly transformed into gypsum or plaster, and inert peroxide of iron ; 

 thus adding a useful ingredient to the components of the marl. This renders 

 the previous exposure or weathering of the marls, doubly important. 



460 1 As to the quantity of marl to be used, so much depends on circum- 

 stances, that it is difficult to give any general rules in regard to it. On heavy 

 clay lands, and such as contain a large supply of vegetable matter, " over- 

 dressing" will not readily come to pass. Dressings of 300 bushels per acre, of 

 mails containing 40 per cent, of carbonate of lime (and proportionally less of 

 those containing' a higher percentage) are quoted by Mr. Muffin, in his "Essay 

 on Calcareous Manures," as being unobjectionable on soils moderately heavy, 

 while on very heavy land, dressings of 500 to GOO bushels w;<s no overdose. 

 Within these limits, a little more or less, the duration of the effect of marling 

 will be approximately proportionate to the quantity employed. That is to say, 

 if the perceptible effect of a dressing of 300 bushels will last fifteen years, that 

 of one hundred will last about five. This, of course, is only very approxi- 

 mately true ; in the example just quoted, for instance, the effect of the 100 

 bushels would not be quite as prominent at any time, as that of the 300, and 

 would, therefore, be likely to last longer in proportion. — Every individual must 

 judge for himself, whether it is more profitable for him to apply a heavy dressing 

 at once, or lighter dressings in more rapid succession. 



460 2 Overdressing with Marl. — On sandy lands, poor in vegetable matter, 

 overdressing happens more easily, and must be guarded against. If at all 

 practicable, the marls ought to be composted, or at least applied conjointly with, 

 vegetable matter of some kind ; most conveniently, in many cases, by being 

 turned under with green crops. 



The effects on acorn crop, of overdressing with calcareous marls, is described 

 by Mr. Kuffin to consist in the paling, yellowing and final drying up, of the 

 young plant, during the months of May and June ; a phenomenon very similar, 

 apparently, to what we see in the "salty spots" of Hinds and Mankin counties. 



Stable manure, or decaying vegetable matter, is stated by him to be an 

 effectual remedy ; even as, if applied from the outset, it is a certain preventive.* 



*As it would not come within the province of the present Keport, to give this 

 subject a discussion as special as might be desirable and proper in the Final 

 Report, I would refer those who intend to practice marling on a large scale, to 

 the work of Mr. Muffin, above quoted, which contains a vast amount of useful 

 practical rules and information on this subject. 



