Philadelphia Florist and Horticultural Journal, 2(9): 273-276 (September 1853)

UNDERDRAINING.

Were we asked to name any single operation that would most improve American agriculture, we should unhesitatingly answer, thorough underdraining. "That," says one, "is a strange idea; my farm, and most of the farms I am acquainted with, suffer more or less from drought every year, and I should prefer more rather than less water on my farm, especially on the grass land." That, my good sir, is precisely what underdraining will do for you. It will remove all excess of water in the fall, winter, and early spring, when the plants need but little; and in the summer time, when plants need large quantities of water, and the undrained soil is very dry, it will make the soil quite moist and supply the plants with sufficient water. "That," you say, "is contradictory; and however plausible it may be in theory, I guess it will not work in practice." In that you are wrong. In this, as in most true agricultural theories, the theory has been induced from practice. Every farmer who has tried underdraining, knows, whether he can understand the cause or not, that his drained land is much drier in a wet time, and more humid in a dry time, than his undrained land, and that it will stand a drought very much better; in fact, that droughts seldom affect his well drained land. Let us examine this a little.

If you take a common sponge, and dip one end into a basin of water, the whole sponge will become thoroughly saturated, the water rising very far above its own level. If you take a narrow glass tube, open at both ends, and plunge one end into water, you will observe the water rise, contrary to the law of gravitation, much higher in the tube than the external surface of the water. Dr. HOOK, when experimenting on this subject, made glass tubes so fine that the water rose in them twenty-one inches above the level of the water in the vessel. The law by which it rises is called capillary attraction, and is explained thus: the particles of water have a stronger affinity for the glass than for other particles of water, and consequently leave them and ascend the glass. The height to which they will ascend is probably in the inverse ratio of the diameter of the tube.

When a soil, especially a retentive one, is underdrained, the water as it percolates through it leaves innumerable small pores; it becomes like a sponge—a reticulated mass of fine tubes. These tubes, when the surface is wetter than the subsoil, carry down the water to the drains below; and when the surface is dryer than the Subsoil, as it is in a drought, these tubes carry up the water to the roots of plants. Underdraining is not built on this theory, but the theory is founded on the practical results of underdraining, and will the more commend itself to practical farmers.

Plants can take their food only in a state of dilute solution. They cannot live and grow without a constant supply of fresh water. Stagnant water is exceedingly deleterious; "no fact is better demonstrated than that agricultural plants cannot thrive, however well manured, so long as their roots are surrounded with stagnant water. The necessity for underdraining rests on these three facts. Not only does underdraining remove all excess of water, and supply it when deficient, but it equalizes the temperature of the soil. In the spring and fall, when a warm soil is so much needed for the germination and maturation of seeds, the thermometer shows that an underdrained soil is several degrees warmer than one that is not drained; while in very hot weather, the case is exactly tho reverse of this. It is a well known fact that vegetation starts much earlier in the spring, and continues later in the fall, on a drained than on an undrained soil.

But beside the beneficial mechanical effect on the soil, underdraining has great chemical action. The removal of stagnant water and the free admission of air in its stead, accelerates the disintegration of minerals as well as the decomposition of organic matter in the soil, rendering them both available as food for plants. Again, the rain, as it falls and filters through a well-drained, loamy soil, carries to the plants one of the most needed and expensive of all the constituents of cereal crops. Our readers need not be told that we mean ammonia. In our article on the Plowing in of Green Crops, in the June number of 1852, will be found some of our reasons for thinking ammonia the most valuable and necessary ingredient in all wheat soils. The rain water which falls on an acre of land in a year, is estimated to contain over 100 lbs. of ammonia, or sufficient for the growth of 17 bushels of wheat. The recent experiments of WAY and THOMPSON have shown that when ammonia is filtered through a soil containing a good proportion of clay, the ammonia is retained in the soil, and the water passes through free from it. Does this throw no light on the cause of the increased crops following thorough underdraining? The other causes we have mentioned are merely concomitants. It is well known that mechanical texture of soil, moisture, heat, electricity, and sunshine, indispensable as they are, will not grow crops unless the required constituents of plants are present in the soil in proper quantity and quality. Does it throw no light on the beneficial effects of summer-fallow on heavy clays. To our mind it gives a satisfactory explanation to these questions that is consistent with experience and well established scientific principles. It is simply, that the ammonia contained in rain water is retained by the soil as the water slowly percolates through it to the drains beneath. In the case of a summer-fallow, the constant plowing, dragging, &c., divides the particles of the soil, for the first few inches in depth, so line that they are capable of retaining all the ammonia brought to the soil during the year on which it is summer-fallowed. This ammonia it retains for the succeeding wheat crop. But even in this case, if the land needs drainage, (and what land that should be summer-fallowed does not?) the full benefit is not obtained; all the rain which falls in the spring, autumn, and winter, when the soil is fully saturated, passes off in surface water, the ammonia it contains along with it, together with a considerable quantity of matter taken from the soil in mechanical solution.

The cost of underdraining is the most potent argument against its adoption. Thirty dollars is considerable money to invest on an acre of land; but it must be remembered that it is a permanent investment—when once well done it will last a century or more. It is not like laying out $7 per acre in guano or other manure, which lasts but for one year, or two at most. It is a perpetual means of obtaining increased crops. The 100 lbs. of ammonia contained in the rain which falls on an acre per annum, cannot be purchased in guano, its cheapest artificial source, for less than $15. Greater part of this is lost on an undrained soil, while on one that is well underdrained the whole of it is or may be retained. The expense of cultivation is less on the drained than the undrained land. You can plow it earlier in the spring and later in the fall; and after heavy rains, when the land not drained is so wet that man nor beast cannot go on it, the drained soil will be in fine condition to work. The whole of the increase in crops obtained from draining must be considered clear profit. We believe one-third increase to be a low estimate; and as this one-third of the entire produce of the farm is clear profit, it will pay a high interest on the thirty dollars invested in underdraining. Any farm which from its location is worth $40 to $100 per acre, if it needs draining, cannot fail to pay a handsome interest for money judiciously laid out in underdraining,

The effect of thorough drainage on the climate of a country, is a subject too extensive and important to be discussed at this time. That it has n marked effect on climate cannot be doubted. Prior to the general adoption of underdraining in England, the wheat crop was generally affected with mildew, rust, smut, and various insects, to such an extent that the crop was quite uncertain; with the introduction of underdraining these blighting effects were removed, while ague, which was common before, is wholly unknown now.

Shade trees and forests, like large bodies of water, are well known to be great moderators of cold in winter and heat in summer. The disappearance of such vast forests has seriously affected the climate of this continent; hence peaches and other fruits are not those certain crops they were twenty years ago. The climatic equilibrium has been disturbed, and must be restored. We must cease to cut down so recklessly the noble forests, and at the same time must plant shade trees. This will have some effect; but we submit, that thorough underdraining will be found the best and most economical means of equalizing the climate, removing the insects, &c., which make such fearful devastation with the crops, and of improving our national agriculture.—Genesee Farmer.