The soils from the three sites studied had similar parent materials of fluviatile and lacustrine origin but occurred on terraces of different geologic age. The slick spots were relatively impermeable with very limited or no growth of vegetation. The diameter of the spots varied from a few inches to fifty feet or more and the shapes were usually irregular.
            Thin A2 horizons of silt loam texture over the high sodium textural B layers, characterized the slick spot soil. The macrostructure of the B2 horizons in the slick spots was extremely unstable but did not appear to be in a true state of dispersion.
            All soils studied exhibited solodized characteristics. The A horizons had been leached with subsequent siliceousness of the layers. The soil association had a silt loam surface texture and generally exhibited textural B horizons of solonetz morphology. The development or morphology of the slick spot soil was solonetz of weak to moderate in grade or distinctiveness. The A horizons of the associated soil were predominantly A2 with occasionally weak, thin A1 characteristics over the A2. The morphology of the associated soil varied from weak to strong solonetz development, generally with textural B horizons.
            The best growth of vegetation was found on the associated soil exhibiting the weakest morphological development. These soils with weak development may represent areas that were churned or reworked by rodents long enough ago that time has allowed for some degree of development to take place. In general, the profile characteristics indicated that the associated soils are the more normal or more mature of the two contrasts. Although there was a range in degree of maturity, most of the profiles examined had prominent A, B, and C horizons. The soil association occurs as complex.
            The change from the non-saline to solodized saline solonetz condition was often found to take place almost abruptly.
            The slick spots were characterized by high percentage of exchangeable sodium and in most cases high soluble salt concentrations. The ions that predominated were sodium, sulfate, and chloride. Gypsum was present in the lower B horizons. The associated soils were non-saline or slightly saline and low in exchangeable sodium percentage.
            The soil association exhibited prominent calcium carbonate accumulations in the subsoils. The degree of cementation of the calcareous layers was related to geologic development. The presence of soluble salts and gypsum over the calcium carbonate in the slick spot soil suggests the upward movement of water.
            The soil reaction of the noncalcareous A and B horizons of all soils studied was frequently acid. Base saturation, in general, was greater than 75 percent on these acid layers.
            There were no appreciable differences in cation exchange capacity between slick spot and associated soils. However, there were differences in cation exchange capacity between the horizons of the profiles. The cation exchange capacity was low in the A horizons, reached a maximum in the B horizons, then again decreased as the underlying sands and gravels were reached.
           The organic matter and total nitrogen content were considerably lower in the slick spot soil than in the associated soils, but with similar carbon-nitrogen ratios.
            High concentrations of exchangeable sodium and soluble salts were not inhibitory to soil microbial activity after other conditions favorable to the soil microbial flora were met. Aggregation appears to be induced by increasing the activity of soil microbiological populations.

(1)  Some of the first theses did not contain an official abstract so we are using the conclusions from his MS thesis as the abstract.