Soil dry aggregate size distribution: effects of soil type and land use

soil structure is an important physical property of soil and has a great impact on the environment and agriculture. dry aggregate size distribution and related soil structure indices are essential parameters in understanding the structural state of the soil. this study was conducted to determine the effects of different soil types and land uses on structure parameters and to relate them to selected soil properties. the investigation was performed on five soil types (arenosols, fluvisols, chernozems, gleysols and solonetz), each from three different locations and under three different land uses (cropland, meadow and forest), so that a total of 135 undisturbed soil samples were collected. dry sieving analysis was performed to obtain eight aggregate size classes (ascs) (>10, 10-5, 5-3, 3-2, 2-1, 1-0.5, 0.5-0.25 and <0.25mm). the results suggest a highly significant impact of soil type on all ascs and structure indices. land use has a highly significant impact on the >10, 5-3 and 3-2 mm ascs. chernozems and gleysols have more favorable structure than arenosols, fluvisols and solonetz. long term cultivation leads to the deterioration of soil structure and the formation of clods. forest soils have a significantly better structure than soils under meadows and croplands. the application of principal component analysis and regression models identifies water retention at -33 kpa, bulk density and ph value as for the most important factors in predicting dmwd and dgmd.