. Cyclopedia of farm crops. Farm produce; Agriculture. FORESTS FORESTS 321 wise destroyed) is constantly gaining in fertility instead of becoming exhausted,—just the reverse of what happens in farming, where every harvest impoverishes the soil by depriving it of a part of its nutritive substances. While farm land must, of necessity, be fairly level, since a slope of 20° renders it unfit for till- ing, and an incline of 25° unfits it even for pasture, gradients up to 45° are still capable of sustaining tree-growth. On slopes from 5° to 30°, the forest finds its true home, producing there more w
. Cyclopedia of farm crops. Farm produce; Agriculture. FORESTS FORESTS 321 wise destroyed) is constantly gaining in fertility instead of becoming exhausted,—just the reverse of what happens in farming, where every harvest impoverishes the soil by depriving it of a part of its nutritive substances. While farm land must, of necessity, be fairly level, since a slope of 20° renders it unfit for till- ing, and an incline of 25° unfits it even for pasture, gradients up to 45° are still capable of sustaining tree-growth. On slopes from 5° to 30°, the forest finds its true home, producing there more wood, and often yielding greater revenues than when grown in the valley. The reason for the increased growth of trees on moderate slopes is to be found in the stimulating effect of favorable exposures with their greater amount of light and air, of more perfect drainage, and of greater protection from wind and frost than is usually found on flat ground. The ability of the forest to grow on situations too poor or otherwise unfit for agriculture led to designating such situations as absolute forest land (Figs. 425-6). To absolute forest land, therefore, belong all territory north of the range of cultivated plants, all steep slopes, gullies, situations too rocky or too dry for agricultural plants, and swamps. It is impossible, of course, always to draw a distinct line of demarcation between absolute forest land and other land, since the soil may be artificially im- proved, as, in the case of swamps by drainage, but such improvements are, as a rule, very costly, and in this country, where there is still a comparative abundance of land, the absolute forest soil may be made profitable without improvements, by devoting it to forest growth, for which it is fitted, as it were, by nature itself. Labor. The raising of agricultural crops demands a great amount of human eft'ort. The land must be plowed, harrowed, manured or otherwise fertilized, the seeds put in the ground, the harvest
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectagriculture, bookyear
