THE SOIL AND ITS CONSERVATION Importance of soil.—The wealth of Illinois is in her sail and her strength lies iii its intelligent development.—Draper.
These significant words, carved on the walls of the building of the State College of Agriculture, at Urbana, are a striking expression of the importance of Illinois soils. The develop ment, progress, and prosperity of the state as a whole depend on the proper use and care of that thin stratum of the earth's crust, only a few inches in thickness, known as the soil. If this thin outer layer of land were entirely removed from the state, the plant, animal, and human life of today would dis appear. If, by careless cultivation and wasteful methods, this soil cover is gradually depleted of its life-sustaining properties, the removal of this greatest of our resources is going on as certainly as if accomplished suddenly and completely. If, on the other hand, a scientific system of permanent agricul ture is established promptly, this invaluable gift of nature may be retained, not only in its present high state of fertility, but it may be returned to its original productiveness and main tained as one of the world's most fertile regions for all time. In considerable areas of the state the original soil may, at relatively small expense, be so improved that the returns will be increased many fold.
Population and soil.—In Illinois, as elsewhere in the world, the people are dependent directly on the products of the soil for sustenance. This is just as true of the people in the over crowded districts of Chicago, many of whose children have never seen a field of growing crops, as it is of the strictly agricultural districts of the state where the boys and girls do their share in the production of staple crops. A11 the people of the state are wholly dependent for their food and clothing on the soil of Illinois and other regions. No large population can be maintained apart from the products of the earth secured through the intelligent practice of agriculture.
More than 60 per cent of the population of the world live on less than S per cent of the land area of the world, not from choice, merely, but from necessity, a necessity based wholly on the productiveness of the soil. The average density of popula tion on this small percentage of the land of the world exceeds 200 persons per square mile, giving an average area of not more than 16 acres per family. The land of Illinois has larger capacity for production than the more densely populated old-world countries. The Illinois lands passed from a state of nature into private ownership for agricultural purposes within the short period of 60 years, 1800 to 1860. In 110 years, 1S00 to 1910, the population of civilized men in Illinois was multi plied by more than 2,200. The population during this period increased from 1 person to 22 square miles, or 3 townships per family, to 100 persons to 1 square mile, or an average of 32 acres per family. This unparalleled increase of population was due primarily to soil fertility which, as time went on, was combined with remarkable commercial opportunities and valuable mineral resources, especially coal, the basis of modern industrial development.
The census returns for 1920 show that Illinois now supports a population of 116 persons per square mile, giving, on an average, 28 acres per family.
Illinois has attracted this large population in the short space of three generations of mankind. The fathers and grandfathers of those now living were the original settlers of Illinois woodland and prairie. In the course of time, Illinois, with its wealth of fertile soil, busy factories, and numerous mines, is sure to be populated as densely as the average of the well-developed old-world regions. This larger population can maintain a high standard of living only if the present and succeeding generations pass on the soil to their successors with unimpaired, and, in many cases, with improved fertility.