After a period of 30 years land abandoned to grass and weeds shows definite gains in N and C, while the soil of adjacent plots under a 5-year rotation of corn, oats, wheat, and 2 years of timothy shows gradual depletion. Subsurface soils of the uncultivated section show higher percentages of these elements than do those of the cultivated section. In the uncultivated section, the pH values increased progressively with each 2-inch increase in depth down to 6 inches; and the total N, C, and P decreased progressively. Much of the P is fixed in the top 2-inch layer. The larger amts. of other constituents in this layer are due largely to accumulation of organic matter. The cation exchange capacity of the uncultivated soils, greatest in the top 2 inches, was higher than in the cultivated soils, because of the accumulation of the acidoid fraction. The effect of leaching and of removal of exchangeable bases by cultivation is reflected in the lower amt. of exchangeable Ca, Mg, and K in the cultivated than in the uncultivated soils.