Evaluation of the Suitability of Fractal Dimension of Soil Aggregates in Assessing Different Soil Management Practices

A major concern of farmers is deterioration of the soil and water resources. Soil management is the most direct way for mankind to interfere with natural processes that may either intensify or hinder soil degradation. Fractal geometry has been widely used to describe heterogeneity in a wide range of natural processes, including physical systems of soil. In this study, the effects of different management practices on soil physical properties have been studied using fractal geometry. Fourteen farms with different soil management practices were selected within Mereg watershed located in Kermanshah province. The management practices information were obtained from the field survey, and used to determine the conditions of the experimental farms. Different soil samples were taken from these farms to determine soil physical properties in the laboratory. Results showed that the fractal dimension of aggregates could reflect the impact of soil management practices on aggregate size distribution. Suitable management practices such as reduced tillage, proper rotation systems, and using manure improved the soil aggregation and reduced fractal dimensions. Intensive tillage, plowing the steep slopes, and improper management of crop residues, on the other hand, enhanced the breakdown of aggregates and increased fractal dimensions of aggregates. Agroforestry system was the best management practices in this area.