Assessment of land use type effect on soil porosity by image processing

This research work carried out to investigate the effects of land use type on soil porosity by image analysis of soil thin sections in Karkaj Agriculture Research Station. Experiments were conducted by studying five soil profiles with different covers of apple and coniferous trees, alfalfa, rapeseed and bare land (no cultivation) and 450 TIFF format images from soil thin sections, were prepared by connected camera to microscope and pores were separated from minerals with the compensator Lambda plate. As a factorial trial with completely randomized design (CRD), undisturbed soil blocks were prepared with three replications from horizons of A or Ap, Bw and C and then soil thin sections were prepared and studied with a polarizing microscope. Obtained results indicated that total area of soil pores in apple and coniferous lands were greater than those in the utilized lands for alfalfa, rapeseed and bare one, that it can be related to root system and organic matter. Also maximum frequency of shape characteristics such as pores roundness and solidity observed in coniferous covered land were greater than those in alfalfa, rapeseed and bare lands. In alfalfa, rapeseed and bare lands the fractal dimension of the pore component (Dmp) and solid component (Dms) were significantly decreased and increased respectively. Therefore, the quantitative and statistical results revealed significant effects of the land use types on soil porosity and microstructure.