The detritus of mica slate and the schistose rocks form moderately friable soils fit for tillage and pasture. Sandstone soils derived from sandstone, are generally poor. The most productive lands in Ireland are situate in the carboniferous limestone plain, which, as shown on the Geological Map, occupies nearly two-thirds of that country. When to the naturally fertile calcareous soils of this great district, foreign matters are added, derived from the disintegration of granite and trappean igneous rocks, as well as from mica slate, clay slate, and other sedementary rocks, soils of an unusually fertile character are produced. Thus the proverbially rich soil of the Goldenvale, situate in the limestone district extending between Limerick and Tipperary, is the result of the intermixture of disintegrated trap derived from the numerous igneous protusions which are dispersed through that district, with the calcareous soil of the valley. Lands of superior fertility occur near the contacts of the upper series of the carboniferous limestone and the shales of the millstone grit, or lower coal series; important examples of this kind will be found in the valley of the Barrow and Nore, etc., etc. For geological arrangement the carboniferous limestone of Ireland has been divided into four series. 1st Series beginning from below the yellow sandstone and carboniferous slate. 2d Series, the lower limestone. 3d Series, the calp series. 4th Series, the upper limestone. Soil derived from 1st Series is usually cold and unproductive, except where beds of moderately pure limestone are interstratified with the ordinary strata, consisting of sandstone and slate-shale. The 2d Series, when not converted by drift, consisting chiefly of limestone-gravel intermixed with clay, usually presents a friable loam fit for producing all kinds of cereal and green crops, likewise dairy and feeding pastures for heavy cattle, and superior sheep-walks. The 3d Series consists of alternations of dark grey shale, and dark grey impure argillo-siliceous limestone, producing soil usually cold, sour, and unfit for cereal crops; but in many districts naturally dry, or which has been drained and laid down for pasture. This soil produces superior feeding grasses, particularly the cock's foot grass. These pastures improve annually, and are seldom cultivated, because they are considered the best for fattening heavy cattle. The 4th Series produces admirable sheep pasture, and, in some localities, superior feeding grounds for heavy cattle, and produces every variety of cereal and green crops. 309%. It is of the utmost importance that the valuator should carefully attend to the mineral composition of the soil in each case, and a reference to the Geological Map will frequently assist his judgment in this respect, the relative position of the subjacent rocks having been determined upon sectional and fossiliferous evidence. He should carefully observe the changes in the quality and fertility of the soil near to the boundaries of different rock formations, and should expect and look for sudden transitions from cold, sterile, clayey soils, as in the millstone grit districts, into the rich unctuous loams of the adjoining limestone districts, which usually commence close to the line of boundary; and similar rapid changes will be observed from barrenness to fertility, along the boundaries of our granite, trap, and schistose districts, and likewise on the border of schistose and limestone districts, the principle being that every change in the composition of the subjacent rocks tends to an alteration in the quality both of the active and subsoils. As it appears from the foregoing that the detritus of rocks enters largely into the composition of soils and other formations, the most trustworthy analysis is supplied, which, compared with the crops usually cultivated, will show their relative value and deficiencies. NOTE. (The table of analysis given by Sir Richard Griffith is less than one page. Those given by us in the following pages of these instructions are compiled from the most authentic sources, and will enable the valuator or surveyor to make a correct valuation. The surveyor will be able, in any part of the world, to give valuable instructions to those agriculturists with whom he may come in contact. We also give the method of making an approximate analysis of the rocks, minerals and soils which he may be required to value. Where a more minute analysis is required, he may give a specimen of that required to be analysed to some practical chemist-such as Jackson, of Boston; Hunt, of Montreal; Blaney, Mariner, or Mahla, of Chicago; Kane, or Cameron, of Dublin; Muspratt, or Way, of England, etc. etc. Table in section 310 contains the analysis of rocks and grasses. Section 310a, analysis of trees and grasses. Section 3106, analysis of grains, hemp and flax. Section 310c, analysis of vegetables and fruit. Section 310d, analysis of manures. Section 310e, comparative value of manures; the whole series making several pages of valuable information. In Canada, the law requires that Provincial Land Surveyors should know a sufficient share of mineralogy, so as to enable them to assist in developing the resources of that country. In Europe, all valuations of lands are generally made by surveyors, or those thoroughly versed in that science; but in the United States a political tinsmith may be an assessor or valuator, although not knowing the difference between a solid and a square. This state of things ought not to be so, and points out the necessity of forming a Civil Engineers' and Surveyors' Institute, similar to those in other countries.) From these tables it will appear what materials are in the formation of the soil, and the requirements of the plants cultivated; thus, in corn and grasses, silica predominates. Seeds and grain require phosphoric acid. Beans and leguminous plants require lime and alkalies. Turnips, beets and potatoes require potash and soda. The soils of loamy, low lands, particularly those on the margins of rivers and lakes, usually consist of finely comminuted detrital matter, derived from various rocks; such frequently, in Ireland, contain much calcareous matter, and are very fertile when well drained and tilled. The rich, low-lying lands which border the lower Shannon, etc., are alluvial, and highly productive. It is necessary that the valuator should enter into his book a short, accurate description of the nature of the soil and subsoil of every tenement which may come under his consideration, and that all valuators may attach the same meaning or descriptive words to them. The following classification will render this description as uniform as possible : Classification of soils, with reference to their composition, may be be comprehended under the following heads, viz: Argillaceous or clayey-clayey, clayey loam, argillaceous, alluvial. Calcareous-limey, limestone gravel, marl. Peat soil-moor, peat. The color of soils is derived from different admixtures of oxide or rust of iron. Argillaceous earths, or those in which alumina is abundant, as brick and pipe clays. The soil in which alumina predominates is termed clay. When a soil consists chiefly of blue or yellow tenacious clay upon a retentive subsoil, it is nearly unfit for tillage; but on an open subsoil it may be easily improved. Clayey soils containing a due admixture of sand, lime and vegetable matter, are well adapted to the growth of wheat, and are classed amongst the most productive soils, where the climate is favorable. Soils of this description will, therefore, graduate from cold, stiff clay soils to open clay soils, in proportion as the admixture of sand and vegetable matter is more or less abundant, and the subsoil more or less retentive of moisture. Loams are friable soils of fine earth, which, if plowed in wet weather, will not form clods. A strong clayey loam contains about one-third part of clay, the remainder consisting of sand or gravel, lime, vegetable and animal matters, the sand being the predominating ingredient. A friable clayey loam differs from the latter by containing less clay and more sand. In this case the clay is more perfectly intermixed with the sand, so as to produce a finer tilth, the soil being less retentive of mois ture, and easier cultivated in wet weather. Sandy or gravelly loams is that where sand or gravel predominates, and the soil is open and free, and not sufficiently retentive of moisture. A stiff clay soil may become a rich loam by a judicious admixture of sand, peat, lime and stable manure, but after numerous plowings and exposure to winter frosts in order to pulverize the clay, and to mix with it the lime, peat, sand, etc. Alluvial soils are generally situated in flats, on the banks of rivers, lakes, or the sea shore, and are depositions from water, the depositions being fine argillaceous loam, with layers of clay, shells, sand, etc. subsoil may be different. The On the sea shore and margin of lakes, the the clay subsoils usually contain much calcareous matter in the form of broken shells, and sometimes thick beds of white marl. The value of the soil and subsoil depend on the proportion of lime it may contain. This may be found by an analysis. (See sequel for analysis.) Rich alluvial soils are the most productive when out of the influence of floods. These soils are classed as clayey, loamy, sandy, etc., according to their nature. Flat lands or holms, on banks of rivers, are occasionally open and sandy, but frequently they are composed of most productive loams. SILICEOUS SOILS. 309j. Sandy soils vary very much in their grade, color and value, according to the quality of the sand. White shelly sands, which are usually situated near the sea shore, are sometimes very productive, though they contain but a very small portion of earthy matter. Gravelly soils are those in which coarse sand or gravel predominates; these, if sufficiently mixed with loam, produce excellent crops. Slatey soils occur in mountains composed of slate rock, either coarse or fine grained. In plowing or digging the shallow soils on the declevities of such places, a portion of the substratum of slate intermixes with the soil, which thus becomes slatey. Rocky soils. Soil may be denominated rocky where it is composed of a number of fragments of rock intermixed with mould. Such soils are usually shallow, and the substratum consists of loose broken rock, presenting angular fragments. CALCAREOUS SOILS. 309k. Calcareous or limestone soils, are those which contain an unusual quantity of lime, and are on a substratum of limestone. These lands form the best sheepwalks. Limestone gravel soil, is where we find calcareous or limestone gravel forming a predominant ingredient in soils. Marly soils are of two kinds, clayey marl, or calcareous matter combined with clay and white marl, which is a deposition from water, and is only found on the margins of lakes, sluggish rivers and small bogs. On the banks of the River Shannon, beds of white marl are found 20 feet deep. When either clayey or white marl enters into the composition of soils, so as to form an important ingredient, such soils may be denominated marly. PEATY SOILS. 3091. Flat, moory soils are such as contain more or less peaty matter, assuming the appearance of a black or dark friable earth. When the peat amounts to one-fourth, and the remainder a clayey loam, the soil is productive, especially when the substratum is clay or clayey gravel. When the peat amounts to one-half, the soil is less valuable. When the peat amounts to three-fourths of the whole, the soil becomes very light, and decreases in value in proportion to the increase of the peat in the soil. Peaty or boggy soils are composed of peat or bog, which, when first brought into cultivation, present a fibrous texture and contain no earthy matter beyond that which is produced by burning the peat. The quantity of ashes left by burning is red or yellow ashes, about oneeighth of the peat, generally one-tenth or one-twelfth in shallow bogs. In deep bogs the ashes are generally white, and weigh about one-eightieth of the peat. Such land is of little value unless covered with a heavy coat of loamy earth or clay. Hence it appears that the value of peaty soil depends on the amount of red ashes it contains. For this reason peaty soils are valued at a low price. NOTE. (Bousingault, in his "Rural Economy," says: "The quality of an arable land depends essentially on the association of its clay and sand or gravel." Sand, whether it be siliceous, calcareous or felspathic, always renders a soil friable, permeable and loose; it facilitates the access of the air and the drainage of the water, and its influence depends more or less on the minute division of its particles.) The following table, given by Sir Richard Griffith, is from Von Thaer's Chemistry, as found by him and Einhoff : Under the head clay, has been included alkalies, chlorides, and supposed to be in fair proportions. The soil in each case supposed to be uniform to the depth of six inches. In the Field Book the following explanatory terms may be used as occasion may require : Stiff.-Where a soil contains a large proportion (say one-half or even more) of tenacious clay; this cracks in dry weather, forming into lumps. Friable.—Where it is loose and open, as in sandy, gravelly or moory lands. Strong.Where it has a tendency to form into clods. Deep. Where the depth is less than 8 inches. Fine or soft.-No gravel: chiefly composed of very fine sand, or soft, light earth, without gravel. Cold.-Parts on a tenacious clay subsoil, and has a tendency, when in pasture, to produce rushes and other aquatic plants. Sandy or gravelly.—A large proportion of sand or gravel. Slatey. Where the slatey substratum is much mixed with the soil. Worn. Where it has been a long time cultivated without rest or manure. Poor. When of a bad quality. Hungry.—When consisting of a great proportion of gravel or coarse sand resting on a gravelly subsoil. On such land manure does not produce the usual effect. The color of the soil and the features of the land ought to be mentioned, such as steep, level, rocky, shrubby, etc., etc. |