Dependence of the aggregate swelling parameters in soddy-podzolic soils on their properties

Abstract

The degree and rate of the aggregate swelling in loamy sandy, loamy, and clayey soddy-podzolic soils of northwestern Russia have been measured using the methods of image analysis. The results of the study have shown that the degree of swelling of the soil aggregates depended on the proportions of the fine (0.005 mm) and sandy fractions, and the rate of the swelling depended on the density of the soil solid phase. A reliable effect of the soil organic matter content on the swelling rate of the studied objects has been established. The aggregates of the arable soddy-podzolic soils with the highest content of organic matter, as well as the aggregates of the native soils, have been characterized by the lowest swelling rates. A method has been developed for the determination of the swelling rate of soil aggregates that has enabled the assessment of the soil structure. The regression dependences of the degree and rate of the aggregate swelling on the properties and composition of soddy-podzolic soils have been plotted.