EASIER DESTRUCTION OF WEEDS. 123 Drained land freezes deeper. This is a matter of great importance to the orchardist, because the roots of the trees remain frozen through the winter, and are not liable to be affected so severely by the vicissitudes of the climate, which often proves so injurious to the fruit trees in the eastern portion of our country.1 Draining deepens the soil, and furnishes a wide feeding-ground for the roots, as before shown. The weeds are destroyed more easily. The difference is just that which the farmer has observed in killing them upon a wet and dry day. In the former case the earth adheres to them, and they soon take root again; while in the latter, they are readily torn up and withered. All aquatic plants are also driven out. The trees themselves become more hardy, bear more abundantly, and continue more healthful; the fruit is less liable to become spotted; the flavor is greatly improved; and the trees are more uniform in growth. A gentleman of England, who had drained a field of ten acres, desired to ascertain the practical result of the aeration of the soil. The field was divided into five sections, each containing an equal number of drains. Leaving that in the centre, and one on each side, he selected the other two for experiment, and conducted the termini of the drains, and supplied them with a ventilator at each end. Imme 1 See Exposure, p. 27. diately after the conclusion of the work a heavy shower fell, and on the next day the difference was very marked in their relative dryness. The land was all planted with the same crop, and the returns from those sections which were aerated was estimated to be one-half more. Prof. Stockhardt, in his "Agricultural Chemistry," as translated by Dr. Henfry, thus enumerates the effects of drainage: "Wet soils become drier. All our cultivated plants are land plants, and these require for vigorous growth a soil which has moisture, but not in that liquid form which it presents in standing water. When the latter is the case, the roots can only penetrate the earth to the depth at which the water stands, and aquatic plants are likely to make their appearance and displace those of land growth. "Some peaty soil becomes too mellow, because air enters it, where the water had previously been, and makes the humus produced by putrefaction decay in too soft a state. 66 "Cold soil becomes warmer, for it now retains the heat of the sun and air, which previously was in great measure expended in producing evaporation. Heavy soil becomes looser, more easily crumbled, and softer; when it dries, finer cracks are formed than in the undrained, tenacious soils, and it is tuore readily worked. 66 Sluggish soil becomes more active and powerful; MANURE MORE EFFECTIVE. 125 for, by becoming more open and warmer, the two great natural processes by which the food of plants is prepared and rendered soluble (weathering and decay) proceed more rapidly, and to a greater depth. Hence the same quantity of manure is more effective on drained than on undrained land. "Finally, production becomes more certain. It is evident the farmer, by draining, changes a fickle and less fertile into a surer and far more productive and grateful soil, and renders it, to a certain degree, independent of the weather, inasmuch as he carries away harmlessly those extremes to which the inhabitants of the northern hemisphere are most commonly exposed. The dread that the rain and snow-water would wash the manure out of the soil, and rob it of its soluble nutriment in filtering through the earth, has proved quite unfounded in deep draining." 11* CHAPTER V. PULVERIZATION. THE IMPORTANCE A CRUMBLING CONSISTENCY OF SOILS NECESSARY A CRUMBLING consistence of the soil is a ne cessary quality to the perfection of its fertility. A tenacious clay is unproductive because it is stiff, and it is therefore rendered an unsuitable pasture for the roots of plants. Being solid, it resists the attempt of the spongioles to extend themselves for food; and even though there be an abundance of pabulum present, still, as they cannot reach it, it is as useless to the economy of plant life as though it did not exist. This tenacity of the soil prevents the air from penetrating and warming it, and also prevents the decomposition of manurial substances. It absorbs too much moisture, and holds it in a PULVERIZATION OF LIGHT SOILS. 127 stagnant condition. We have already demonstrated, in the chapter on "Drainage," that water should be in motion, by percolation, to be beneficial. Clay soils, or those having such a subsoil, prevent the free action of drains, because the impervious clayey stratum holds in check the water in its flow toward the pipes. But this will be again considered. Soils are often unfertile because of their too light consistency. Such land may be made productive by pulverization. The idea which first presents itself is, that such a course would render it lighter, and consequently more sterile. We argue, however, that its openness is decreased by such treatment, and its firmness augmented. The coarse particles of the soil become disintegrated by frequent exposure to the atmosphere, and they consequently lie more compactly in proportion as their size is lessened. A practical illustration is at hand. A gentleman, when purchasing an estate in Massachusetts, hesitated at first, on account of the extreme lightness and sterility of the land. The surface-soil was but two inches in depth, while the subsoil consisted of but four, of light yellow, sandy loam, which rested upon sand and gravel. The depth of cultivation in the neighborhood was not more than from three to four inches, as the farmers dreaded to plough up the sand, because it was thought that it still more impoverished the soil. Contrary to these agricultural traditions, he ploughed |