Imágenes de páginas

** of grass, and clover. All our experience and observatioi "deny the doctrine that roots only ramblo when they art "stinted of food; that six inches well manured is quite "enough, better than more. Ask the J«rscyman; h "will show you a parsnip as thick as your thigh, and as "long as your leg, and will tell you of the advantages of "14 feet of dry soil. You will hear of parsnips whose "loots descend to unsearchable depths. We will not "appeal £o the Kentucky carrot, which was drawn out "by its roots at the antipodes; but Mr. Mechi's, if we "remember right, was a dozen feet or more. Three years "ago, in a midland county, a field of good land, in good "cultivation, and richly manured, produced a heavy crop "of cabbages. In November of that year we saw that "field broken into in several places, and at the depth of

* four feet the soil (a tenacious marl, fully stiff enough for

* brick-earth) was occupied by the roots of cabbage, not sparingly—not mere capillae—but fibres of the size of

"small pack-thread. A farmer manures a field of four or "five inches of free soil reposing on a retentive clay, and "sows it with wheat. It comes up, and between the ker"nel and the manure, it looks well for a time, but anon it sickens. An Irish child looks well for five or six years, but. after that time potato-feeding, and filth, and hard"ship,, begin to tell. You ask what is amiss with the K wheat, and you are told that when its roots reach the 'clay, they are poisoned. This field is then thorough"drained, deep, at least four feet. It receives again from "the cultivator the previous treatment; the wheat comes "up well, maintains throughout a healthy aspect, and "gives a good return. What has become of the poison? "We have been told that the rain water filtered through "the soil has taken it into solution or suspension, and has "carried it off througL the drains; and men who assume "to be of authority put forward this as one of the adw vantages of draining. If we believed it, we could not "advocate draining. We really should not have the face "to tell our readers that water, passing through soils con '' taining elements prejudicial to vegetation, would carry "them off, but would leave those which are beneficial be"hind. We cannot make our water so discriminating; the "general merit of water of deep drainage is, that it con"tains very little. Its perfection would be that it should "contain nothing. We understand that experiments are "in progress which have ascertained that water, charged "with matters which are known to stimulate vegetation, "when filtered through four feet of retentive soil, comes "out pure. But to return to our wheat. In the first case "it shrinks before the cold of evaporation and the cold of "water of attraction, and it sickens because its feet are "never dry; it suffers the usual maladies of cold and wet. "In the second case, the excess of cold by evaporation "is withdrawn; the cold water of attraction is removed "out of its way; the warm air from the surface, rushing "in to supply the place of the water which the drains re"move, and the warm summer rains, bearing down with "them the temperature which they have acquired from "the upper soil, carry a genial heat to its lowest roots. "Health, vigorous growth, and early maturity are the "natural consequences. *********

"The practice so derided and maligned referring to "deep draining has advanced with wonderful strides. "We remember the days of 15 inches; then a step to 20; a "stride to 30; and the last (and probably final) jump to 50, a "few inches under or over. We have dabbled in them all, ■" generally belonging to the deep section of the day. We "have used the words 'probably final,' because the first "advances were experimental, and, though they were jus"tified by the results obtained, no one attempted to ex "plain the principle on which benefit was derived from "them. The principles on which the now prevailing 'depth is founded, and which we believe to be true, go "far to show that we have attained all the advantage! "which can be derived from the removal of water in "ordinary agriculture. We do not mean that, even in the "most retentive soil, water would not get into drains "which were laid somewhat deeper; but to this there "must be a not very distant limit, because pure clay, lying l< below the depth at which wet and drought applied at "surface would expand and contract it, would certainly "part with its water very slowly. We find that, in coal "mines and in deep quarries, a stratum of clay of only a "few inches thick interposed between two strata of per"vious stone will form an effectual bar to the passage of '1 water; whereas, if it lay within a few feet of the sur"face, it would, in a season of heat and drought become "as pervious as a cullender. But when we have got rid "of the cold arising from the evaporation of free water, "have given a range of several feet to the roots of grass "and cereals, and have enabled retentive land to filter "through itself all the rain which falls upon its surface, "we are not, in our present state of knowledge, aware of "any advantage which w'ould arise from further lowering "the surface of water in agricultural land. Smith, of "Deanston, first called prominent attention to the fertiliz"ing effects of rain filtered through land, and to evils pro"duced by allowing it to flow off the surface. Any one "will see how much more effectually this benefit will be "attained, and this evil avoided, by a 4-foot than a 2-foot "drainage. The latter can only prepare two feet of soil "for the reception and retention of rain, which two feet, "being saturated, will reject more, and the surplus must 'run off the surface, carrying whatever it can find with it. "A 4-foot drainage will be constantly tending to have four "feet of soil ready for the reception of rain, and it will "take much more rain to saturate four feet than two. "Moreover, as a gimlet-hole bored four feet from the sur"face of a barrel filled with water will discharge much * moie in a given time than a similar hole bored at the "depth of two feet, so will a 4-foot drain discharge in a "given time much more water than a drain of two feet. "One is acted on by a 4-foot, and the other by a 2-foot

1 pressure."

If any single fact connected with tile-drainage is established, beyond all possible doubt, it is that in the stiffest clay soils ever cultivated, drains four feet deep will act effectually; the water will find its way to them, more and more freely and completely, as the drying of successive years, and the penetration and decay of the roots of successive crops, modify the character of the land, and they will eventually be practically so porous that,—so far as the ease of drainage is concerned,—no distinction need, in practice, be made between them and the less retentive loams. For a few years, the line of saturation between the drains, as shown in Fig. 11, may stand at all seasons considerably above the level of the bottom of the tile, but it will recede year by year, until it will be practically level, except immediately after rains.

Mr. Josiah Parkes recommends drains to be laid

"At a minimum depth offour feet, designed with the two-fold object ol not only freeing the active soil from stagnant and injurious water, but of converting the water falling on the surface Into an agent for fertilizing; no drainage being deemed efficient that did not both remove the water falling on the surface, and i keep down the subterranean water at a depth exceeding the power of capillary attraction to elevate it near the Surface.'"

Alderman Mechi says:

"Ask nineteen farmers ont of twenty, who hold strong clay laud, and they will tell you it is of no nse placing deep four-foot drains in such soil* —the water cannot get in; a horse's foot-hole (without an opening under it) will hold water like a basin; and so on. Well, five minute* after, you tell the same farmers you propose digging a cellar, well bricked, six or eight feet deep; what is their remark f 'Oh! it's of no use your making an underground'cellar in our soil, you can't keep tne water Out!' Was there ever such an illustration of prejudice as this f What is a drain pipe but a small cellar full of air? Then, again, common tense tells us, you can't keep a light fluid under a heavy one. You might as well try to keep a cork under water, as to try and keep air undei water. 'Oh 1 but then our soil ts n't porous.' If not, how can It hold water Bo readily * I am led to these observations by the strong controversy I am having with some Esses folks, who protest that I am mad,oi foolish, for placing 1-inch pipes, at four-foot depth, in strong clays. It is in vain I refer to the numerous proofs of my soundness, brought forward by Mr. Parkes, engineer to the Royal Agricultural Society, and confirmed by Mr. Fusey. They still dispute It. It is in vain I tell them I cannot keep the rainwater out of socketed pipes, twelve feet deep, that convey a spring to my farm yard. Let us try and convince this large class of doubters; for it is of national importance. Four feet of good porous clay would afford a far better meal to some strong bean, or other tap roots, than the usual six inches; and a saving of $4 to $5 per acre, in drainage, is no trifle.

"The shallow, or non-drainers, assume that tenacious subsoils are Impervious or non-absorbent. This is entirely an erroneous assumption. If soils were impervious, how could they get wet f

"I assert, and pledge my agricultural reputation for the fact, that then are no earths or clays in this kingdom, be they ever so tenacious, that will not readily receive, filter, and transmit rain water to drains placed five or more feet deep.

"A neighbor of mine drained twenty inches deep in strong clay; th« ground cracked widely; the contraction destroyed the tiles, and thi rains washed the surface soils into the cracks and choked the drains. Ht has since abandoned shallow draining.

"When I first began draining, I allowed myself to be overruled bf my obstinate man, Pearson, who insisted that, for top water, two fea> was a sufficient depth in a veiny soil. I allowed him to try the exper: ment on two small fields; the result was, that nothing prospered; ani I am redraining those fields at one-half the cost, five and six feet deep at intervals of 70 and 80 feet.

"I found Iron-sand rocks, strong clay, silt, Iron, etc., and an enormous quantity of water, all below the 8-foot drains. This accounted at once for the sudden check the crops always met with in May, when they wanted to send their roots down, but could not, without going into stagnant water."

"There can be no doubt that it is the depth of the drain which regulates the escape of the surface water in a given time; regard being had, as respects extreme distances, to the nature of the soil, and a due capacity of the pipe. The deeper the drain, even in the strongest soils, the qiikket the water escapes. This is an astounding but certain fact:

"That deep and distant drains, where a sufficient fall can be obtained, are by far the most profitable, by affording to the roots of the plants a greater rangu for food."

Of course, where the soil is underlaid by rock, less tnau four feet from the surface; and where an outlet at that depth cannot be obtained, we must, per force, drain lew

« AnteriorContinuar »