Everybody knows that if a board or cloth be put upon the ground, in dry weather, the earth under it will remain moist—its aqueous particles being checked in their passage upward. If a shovelful of fine manure be laid in a heap upon a spot of ground, the same effect will be produced. Gardeners are accustomed to cover the earth about shrubs with an inch or two of fine sand; experience teaching them that it preserves the moisture of the soil. Now, if the soil, instead of being covered with sand, or light manure, be itself pulverized, the same effect will be produced—and for reasons which will appear. When the soil is compact the moisture ascends from particle to particle without obstruction. Every crevice which separates the particles of earth, checks the passage of the moisture. This may be more readily seen in an analogous case—the transmission of heat. Take two nail-rods, lay the end of one in the fire; divide the other into inch pieces and lay them in a row from the fire, each piece touching the other. The transmission of heat in the rod made up of pieces will be checked at each point of division, while the uncut rod will heat rapidly. On this principle, an iron chain two feet long, with one end thrust into fire, will not transmit heat through its length near so soon as a solid bar of the same length.
If this reasoning be true, and experience bears it out, the plow should be kept running in dry times to save a crop from drought. But if the farmer has neglected his corn, waiting for rain, and begins to plow after his ground is very dry, and plows deep, _breaking the roots_ of his corn, the crop will be “fired;” for, in this case, besides the evaporation from the leaves and the dryness of the soil, he commences breaking the roots by which the crop drinks what little water there may be left for it. Of course it despairs when it is attacked on one side by the heat, and on the other by the foolish farmer, and underneath by a treacherously dry soil. Begin, then, early, and plow often, and you may defy dry summers and cram your crib with hearty crops of corn.
BREAKING THE ROOTS.—Many farmers study to break the roots of their corn. We have heard them boast of ripping them up with a big plow till they clogged it up like bundles of yarn. It is done by some because others do it; those who attempt to reason, say, that if a root be broken it immediately puts out many more from the point of breakage; and the practice of root-pruning fruit-trees is cited, to show that the fruitfulness of a plant is increased by reducing the root and checking the growth of the wood. It is not true that the fruitfulness of a tree is increased by root-pruning, but, it is made to yield its fruit _earlier_. It is a device to bring trees rapidly into bearing. A pear-tree (grafted) requires from five to eight years before it is matured enough to commence bearing. By mutilation of root, bending of branches, or by a poor gravelly soil, the tree is partially forbidden to grow, and obliged to ripen its wood and fit it for fruit-bearing. But had it grown to its natural size, it would then have borne even more fruit than when dwarfed.