Plains of the upper half of the Mississippi Valley. A layer of glacial drift from 10 to 200 feet in thickness extends over all of the state except the northwest corner and the extreme southern counties. The western portion of the glaciated upland along the Mississippi River is deeply covered by a brown silty loam known as loess. The surface of Illinois is a vast grassy plain sloping gently to the southwest, and traversed by the valleys of 275 streams. It is one of the most level states in the Union, with a descent rarely exceeding one foot to the mile, so that swamps are numerous; and it is probable that at no very remote geological period a large part of the land was covered by a shallow lake. The soil is a fine compact back loam, 10 to 15 inches deep, entirely free from stones and gravel, of inexhaustible fertility, and largely underlaid by yellow clay. The absence of trees from the prairies is partly explained by the intense prairie fires which annually burned the dry grasses, and partly by the compactness of the soil which excludes from the roots of trees the oxygen required for oxidation. Referring to the changing color of the soil, J. R. Wooldridge, President of the Illinois State Beekeepers’ Association, writes:
“Southward from Effingham the soil loses its black color, becoming a reddish clay, much spotted with white patches, and for about 60 miles is less productive; but from there on to Cairo it produces great crops of peaches and apples. Though the soil on the uplands of this region is red clay, it has proven to be a world-beater when it comes to producing fruits and vegetables. The soil of the valleys is much darker in color, and most of it is very productive also.”
The richest and most varied forest in the north temperate zone is found in the lower Wabash Valley in southeastern Illinois, where 107 species of trees occur, and 75 species have been counted in an area of less than a square mile. The flora contains a great variety of flowering plants, but most of the species are of only incidental value to the beekeeper. The larger part of the population is engaged in agriculture.
While the different sections of Illinois vary in altitude, climate, and soil, the whole state is admirably suited to agricultural purposes. In the northern three-fifths of the state, especially in the central portions, there is an immense acreage of corn and oats. This section is often referred to as the “com belt.” A great area in the southern two-fifths of the state is devoted to the growing of orchard fruits, whence it is called the “fruit belt.” Apples contribute three-fifths of the crop, while peaches rank next in importance. There is no sharp dividing line between these two belts, as cereals are largely grown in the southern part, and fruit trees in the northern part of the state. But the acreage of corn, oats, and wheat in the central portion of the state is so large that it reduces the extent of the bee pasturage, and is unfavorable to beekeeping.
Very large yields of honey have been obtained in the two northern tiers of counties. The surplus in this section is stored from white clover, sweet clover, and heartsease. Fifty years ago heartsease was hardly known; but now it is important. A little basswood honey is sometimes obtained, but not often. When the temperature and rainfall are both favorable white clover may yield a phenomenal surplus, as at Marengo, McHenry County, in 1913, when 72 colonies averaged 266 sections of comb honey. At Rockford, Winnebago County, there have been four good honey flows from white clover in the past eight years, the largest flow coming after a very wet fall. There are many small apiaries which perhaps average 15 colonies. Around Chicago there is a good dairy region, and as the result of the rapid increase of sweet clover in recent years the production of honey has increased enormously, sweet clover being the main source.
This sweet-clover area extends southward into Will and Grundy counties, par-