Clay soil

“ We have seen that clay holds water and is very wet and sticky in winter, while in summer it becomes hard and dry, and is liable to crack badly. "It greets a' winter and girns a' summer," as one of Dr John Brown's characters said of his soil. Clay soils are therefore hard to dig and expensive to cultivate: the farmer calls them heavy and usually prefers to put them into grass because once the grass is up it lasts as long as it is wanted and never needs to be resown. ”

“ The third way to improve clay soils is by using coarse vegetable manures, large quantities of stable, manures, ashes, chips, sawdust, sand, or any similar materials, which will tend to break up and lighten the soil mechanically. Lime and land plaster are also valuable, as they cause chemical changes which tend to break up clayey soils.
The fourth thing to do in treating a garden of heavy soil is to plow, ridging up as much as possible, in the fall, thus leaving the soil exposed to the pulverizing influences of weather and frost. ”

“ CLAY SOILS are stiff, wet, heavy and usually "cold." For garden purposes, until properly transformed, they hold too much water, are difficult to handle, and are "late." But even if there be no choice but a clay soil for the home garden, the gardener need not be discouraged. By proper treatment it may be brought into excellent condition for growing vegetables, and will produce some sorts, such as celery, better than any warm, light, "garden" soil. The first thing to do with the clay soil garden, is to have it thoroughly drained. ”

“ The garden soil after drying is not as stiff as the clay nor as loose as the sand and humus. This is because it is very likely a mixture of all three, the sand and the humus checking the baking. This teaches us that it is not a good plan to work soils when they are wet if they are stiff and sticky; and that our stiff clay soils can be kept from drying hard or baking by the use of organic matter. ”

“ When to these essential physical properties of clay, there is added the [Pg 84] fact that usually the clay-substance as it exists in soils contains the most finely pulverized and most highly decomposed portions of the other soil-minerals, and therefore the main part of the available mineral plant-food, it is easy to understand why soils containing a good supply of clay should be called and considered “strong” land by the farmers of all countries. “Poor” clay soils are exceptional ”

“ A clay soil, in which, in addition to the predominating alumina, there is a fair proportion of lime, may be regarded as the most fertile for all purposes; but we have few such in Britain, our clays being mostly of an obdurate texture, retentive of moisture, and requiring much cultivation, and containing, moreover, salts of iron in proportions and forms almost poisonous to plants. But there are profound resources in most clays, so that if it is difficult to tame them, it is also difficult to exhaust them. ”

“ It will be observed that in all cases where a crop growing on a clay soil could be compared with the same on a lighter soil, the moisture required to keep the crop in good condition was very much greater in the clay than in the loam or sandy soils. ”

“ Whereas the sand and the loam will remain in fairly good condition when dry, the clay will have become "puddled," i. e., the particles will have run together and made a hard, compact mass. Thus it is found in practice that clay soils must be handled with far more care and intelligence than is required for the sand and loams, if the texture is to be kept perfect.
Experiment No. 4.—If, in the experiment above suggested, the clay soil is mixed with leaf-mould, or humus soil, from the woods, [118] it will be found to act very differently. ”

“ The very first thing to be done with a tenacious and obstinate clay soil is to have it dug out and carted away bodily, and its place supplied with good fresh loam. This would be a serious job if there were several acres. ”

“ It will, therefore, render clay soils more open, and may thus, when mixed in large quantity, produce a permanent amelioration in the mechanical texture of many stiff wheat soils. It cannot itself undergo any chemical change that is likely so to alter its constitution as to make it a more useful chemical constituent of the soil than before. Any saline matter we may suppose to be set free could be far more cheaply added in the form of a top-dressing to the soil. ”

“ The clay soil really needs air. The good bacteria will not work without this. So spade the soil up in the fall, and leave it weathering in huge lumps. Sand or ashes added in the spring helps the air question too. A sprinkling of lime over the surface tends to sweeten the entire soil; for clay soil, so often too wet, is liable to get sour. Lime also adds another plant food called calcium. It would not be bad to add some humus in order to have an even greater supply of nitrogen. ”

“ In the arid region, on the contrary, a great many sandy or silt soils, very poor in clay, exert fully as much chemical absorption as clay soils, and are no more liable to the washing-out of soluble fertilizers introduced than are the latter. For the chemical absorption lies chiefly in the zeolitic portion of the soil (see above chap. 3, p. 37) , which in the humid region accumulates in the clay, while in the arid it remains encrusting the sand and silt grains. ”

“ Soils containing enough clay to make them retentive of moisture become too compact when rains beat upon the ground, as usually happens after the planting of spring crops. A deep and close cultivation of corn and potato plants after they appear in the row helps to restore the condition created by the plow and harrow, and often is the best practice. There is some sacrifice of roots, but the gain far exceeds the loss. It may be necessary to give a second such cultivation when a clay soil is deficient in organic matter, but the root-pruning is a handicap. ”

“ It should be applied in the fall, in the form of strawy stable manure, and buried deeply. Leaves also are a valuable addition. Liming is good, as this causes the flocculation of the clay particles and renders the soil more open and permeable by air and water. The addition of sand, sifted coal ashes, or wood ashes serves the same purpose. Clay soils are benefited by being plowed or spaded in the fall and left rough over the winter. This allows the frost to penetrate more readily, resulting in the breaking up and disintegration of the clods. ”

“ A poor sandy soil is necessarily a nearly barren one; because it will not retain either water, or the nutritious juices from manure, long enough to afford nourishment to the plants grown upon it; and it is obvious that a soil of this kind can only be rendered fertile by mixing it with clay; which would change it into a sandy loam.
A stiff clay is unfertile from its attracting moisture and retaining it round the roots of the plants till they become swollen and unhealthy. ”

“ As rain generally succeeds, it is soon washed down to the roots of the plants, and gives them a vigor and strength, which, to those who never made the experiment, is astonishing. The lime, sand, and rubbish, are particularly useful in breaking the tenacity of stiff clays. In a clay soil, where coal was very cheap, the clay was slightly burned in the field, and spread over the surface, as the cheapest way of subduing the coarseness and stiffness of the soil. ”

“ It is said that clay particles reach a degree of fineness equal to 1/2500 of an inch. Clay itself, when wet and kneaded, becomes plastic and adhesive and is thus easily distinguished from sand. Because of these properties, clay is of great value in holding together the larger soil grains in relatively large aggregates which give soils the desired degree of filth. Moreover, clay is very retentive of water, gases, and soluble plant-foods, which are important factors in successful agriculture. Soils, in fact, are classified according to the amount of clay that they contain. ”

“ Should permeable soil lie between the top stratum and a bed of clay, water will accumulate upon the clay, make it slimy and cause a flow upon the bed; for example, when a thin bed of vegetable earth rests upon gravel, sand, or peat, and that upon clay, water will percolate, and perhaps air, through the top soils, and may cause them to slip upon the clay-bed. Also should a layer of clay overlie permeable strata, as clay upon sand, or clay upon gravel, unless it is sufficiently thick and solid to prevent infiltration, it may slide upon the permeable soil as its lower surface becomes wet. ”

“ Clay, Dense Marls, and Alluvial Soils generally, are apt to be cold and damp. Water is retained in them, and is often very impure. Thorough drainage improves a clay soil, and a house on a clay soil may be so constructed, as not to be damp.
9. Cultivated Soils are not necessarily unhealthy; but
10. Made Soils are always to be carefully avoided, as sites for houses. The materials with which inequalities have been filled up are commonly the contents of dust-bins, or some other refuse. The gradual putrefaction of organic matters renders the air about the houses impure. ”

“ By the removal of the water, the physical properties of the soil also are in a remarkable degree improved. Dry pipe-clay can be easily reduced to a fine powder, but it naturally, and of its own accord, runs together when water is poured upon it. So it is with clays in the field. The soil expands, becomes close and adhesive, and excludes the air from the roots of the growing plant,—the access of which air appears to be almost an essential element in the healthy growth of the most important vegetable productions. ”

“ A hard clay is very unproductive. But so disintegrated that plants can grow in it, it produces a great crop. This is because clay is of so close a texture, that when mixed with manure, turf, sand, or muck, although friable, it retains more moisture, than sand or ordinary loam. ”

“ It may be a clay-soil, a sand-soil, a calcareous soil, as the surface is composed of clay, or sand, or clay strongly mixed with lime, etc.
Subsoil.—The earth lying below the ordinary depth to which the plow or spade penetrate. Sometimes it has hardened by the running of the plow over it for a series of years; then it is called pan, as hard-pan, clay-pan, etc. It is sometimes of the same nature as the top-soil, as in clay-lands; in others it is a different earth; as when a coarse gravel underlies vegetable mold, or when clay lies beneath sandy soil. ”

“ Fig. 47. Highly cultivated sand in Kent. Gooseberries are growing in the foreground, vegetables behind, and hops in background
A sandy soil is in so many ways the opposite of a clay soil that we shall expect to find corresponding differences in the look of the country. A sandy soil does not hold water: it may get water up from the subsoil to supply the plant (see p. 66) , or, if it happens to lie in a basin of clay, it may even be very wet: otherwise it is likely to be too dry for ordinary plants. ”

“ For this reason porous soil, covered with stout turf and underlaid by a sandy or gravelly subsoil, is best. A site on clay soil, or where the ground water approaches the surface, is damp, cold, and unhealthful. ”

“ On soils that are light, again, which naturally contain little clay, the grasses will thrive more rapidly, a thick sward will be sooner formed, but the tendency of the rains to wash out the clay may prevent them from ever attaining that luxuriance which is observed upon the old pastures of the clay lands.
On undrained heaths and commons, and generally on any soil which is deficient in some fertilizing element, neither abundant herbage, nor good crops of any other kind, can be expected to flourish. ”

“ After standing a few hours the muddy water has become clear, and a deposit of a yellowish substance has collected in the bottom of the dish. We will carefully pour off the water and examine what remains. This fine soft mud we call clay. As it dries and becomes hard it shrinks and cracks, and thus breaks up into little pieces. Clay forms a greater or lesser part of all soil. Clay soil is very sticky when it is wet, as you will be sure to remember if you have tried to walk over it. When soil is formed largely of clay we speak of it as a heavy soil. ”

“ In treating of the power of the soil to absorb moisture, we have shown that a clay soil will absorb more than half its weight and bulk of water, and that it holds more water than any other soil, with, perhaps, the single exception of peat. ”

“ Decaying organic matter or humus is really the life of the soil and it is greatly needed in most of the farm soils of the eastern part of the country. It closes the pores of sandy soils and opens the clay, thus helping the sand to soak up and hold more moisture and lessening excessive ventilation, and at the same time helping the roots to take a firmer hold. It helps the clay to absorb rain, helps it to pump water faster, helps it to hold water longer in dry weather, increases ventilation, favors root penetration and increases heat absorption. ”

“ Beyond the immediate banks of the Platte the soil is either sandy, quickly absorbing water, or it is a hard, cold, unwholesome clay, which long retains muddy pools, black with decayed vegetation, and which often, in the lowest levels, becomes a mere marsh. The wells deriving infiltration from the higher lands beyond are rarely more than three feet deep; the produce is somewhat saline, and here and there salt may be seen efflorescing from the soil around them. ”

“ A stiff clay, on the other hand, will in a single night absorb sometimes as much as a 30th part of its own weight, and a dry peat as much as a 12th of its weight; and, generally, the quantity thus drunk in by soils of various qualities, is dependent upon the proportions of clay and vegetable matter they severally contain. We cannot fail to perceive from these facts, how much of the productive capabilities of a soil is dependent upon the proportions in which its different earthy and vegetable constituents are mixed together. ”