Impact of Land Use Changes on some Soil Micromorphological Features in Rakat Watershed, Eastern Khuzestan Province

The objective of this study was to investigate the impact of land use change (forest and rangelands to agriculture) on some micromorphological indices of soil quality in part of Rakat watershed, southwest of Iran. Accordingly, intact soil samples from 0-15 and 15-30 cm depths were collected from the above-mentioned land uses, and microstructure, type and abundance of voids, redoximorphic features, and humic substances were compared. The results showed that in the natural forest use, most of the voids are in the form of macropores, whereas after their conversion to agriculture, these types of voids have little development. In natural rangelands uses, voids were mainly oriented channels and of macropore type, but after switching from pasture to agriculture, they were mainly of vughy type. The results showed that natural forests (27.73%) and natural grasslands (22.28%) had more abundance of voids than forest to agriculture (19.01%) and grassland to agriculture (18.62%) land uses. In both natural forests and pasture land uses, various types of iron and manganese nodules, coatings, hypo-coatings, and quasi-coatings were significantly higher than agricultural land uses.