Evaluation of Soil Structure of Medium and Fine Textured Soils in situ

Evaluation of soil structure of some medium and fine textured soil was done by studying the morphological features of the profiles, infiltration rate and penetration force, determined in silu. The data on clay content and water stable aggregates were used to characterize the deviation of these parameters. A highly significant linear negative correlation was noted among average penetration force and log infiltration rate Higher correlation coefficient values were obtained when the soils were grouped as fine textured (clays) and medium textured (non-clays) ones. This relationship among the parameters differentiate the well developed, moderate and poorly structured soils and thus could be used as yardstick for the evaluation of soil structure. Clay was an important factor in the relationship among penetration force and infiltration rate as the degree of correlation improved significantly when clay content was introduced as the third variable in the multiple regression analysis. These results indicate that individual regression line for each soil group is feasible for the critical evaluation of their structure.