Draining has been defined, "The art of rendering land not only so free of moisture as that no superfluous water shall remain in it, but that no water shall remain in it so long as to injure, or even retard the healthy growth of plants required for the use of man and beast."
Some plants grow in water. Some even spring from the bottom of ponds, and have no other life than such a position affords. But most plants, useful to man, are drowned by being overflowed even for a short time, and are injured by any stagnant water about their roots. Why this is so, it is not easy to explain. Most of our knowledge on these points, is derived from observation. We know that fishes live in water, and if we would propagate them, we prepare ponds and streams for the purpose. Our domestic animals live on land, and we do not put them into fish-ponds to pasture. There are useful plants which thrive best in water. Such is the cranberry, notwithstanding all that has been said of its cultivation on upland. And there are domestic fowls, such as ducks and geese, that require pools of water; but we do not hence infer that our hens and chickens would be better for daily immersion. All lands, then, require drainage, that contain too much water, at any season for the intended crops.
This will be found to be an important element in our rule. Land may require drainage for Indian corn, that may not require it for grass. Most of the cultivated grasses are improved in quality, and not lessened in quantity, by the removal of stagnant water in Summer; but there are reasons for drainage for hoed crops, which do not apply to our mowing fields. In New England, we have for a few weeks a perfect race with Nature, to get our seeds into the ground before it is too late. Drained land may be plowed and planted several weeks earlier than land undrained, and this additional time for preparation is of great value to the farmer. Much of this same land would be, by the first of June, by the time the ordinary planting season is past, sufficiently drained by Nature, and a grass crop upon it would be, perhaps, not at all benefitted by thorough-drainage; so that it is often an important consideration with reference to this operation, whether a given portion of our farm may not be most profitably kept in permanent grass, and maintained in fertility by top-dressing, or by occasional plowing and reseeding in Autumn. It is certainly convenient to have all our fields adapted to our usual rotation, and it is for each man to balance for himself this convenience against the cost of drainage in each particular case.
What particular crops are most injured by stagnant water in the soil, or by the too tardy percolation of rain-water, may be determined by observation. How stagnant water injures plants, is not, as has been suggested, easily understood in all its relations. It doubtless retards the decomposition of the substances which supply their nutriment, and it reduces the temperature of the soil. It has been suggested, that it prevents or checks perspiration and introsusception, and it excludes the air which is essential to the vegetation of most plants. Whatever the theory, the fact is acknowledged, that stagnant water in as well as on the soil, impedes the growth of all our valuable crops, and that drainage soon cures the evil, by removing the effect with its cause. And the remedy seems to be almost instantaneous; for, on most upland, it is found that by the removal of stagnant water, the soil is in a single season rendered fit for the growth of cultivated crops. In low meadows, composed of peat and swamp mud, in many cases, exposure to the air for a year or two after drainage, is often found to enhance the fertility of the soil, which contains, frequently, acids which need correction.
INDICATIONS OF TOO MUCH MOISTURE.
It has already been suggested, that motives of convenience may induce us to drain our lands—that we may have a longer season in which to work them; and that there may be cases where the crop would flourish if planted at precisely the right time, where yet we cannot well, without drainage, seasonably prepare for the crop. Generally, however, lands too wet seasonably to plant, will give indications, throughout the season, of hidden water producing its ill effects.
If the land be in grass, we find that aquatic plants, like rushes or water grasses, spring up with the seeds we have sown, and, in a few years, have possession of the field, and we are soon compelled to plow up the sod, and lay it again to grass. If it be in wheat or other grain, we see the field spotted and uneven; here a portion on some slight elevation, tall and dark colored, and healthy; and there a little depression, sparsely covered with a low and sickly growth. An American traveling in England in the growing season, will always be struck with the perfect evenness of the fields of grain upon the well-drained soil. Journeying through a considerable portion of England and Wales with intelligent English farmers, we were struck with their nice perception on this point.
The slightest variation in the color of the wheat in the same or different fields, attracted their instant attention.
"That field is not well-drained; the corn is too light-colored." "There is cold water at the bottom there; the corn cannot grow;" were the constant criticisms, as we passed across the country. Inequalities that, in our more careless cultivation, we should pass by without observation, were at once explained by reference to the condition of the land, as to water.
The drill-sowing of wheat, and the careful weeding it with the horse-hoe and by hand, are additional reasons why the English fields should present a uniform appearance, and why any inequalities should be fairly referable to the condition of the soil.