سهیلا سادات هاشمی

The aim of this study was to evaluate the physico-chemical properties and clay mineralogy in paddy soils of Doroud region in Lorestan province. Seven profiles were sampled and described and all soil profiles were classified in Inceptisols and Entisols orders. According to the results, clay content of soils due to waterlogging was high. Due to the reduction Conditions, pH of all soil samples was nearly neutral. Due to the flooding and accumulation of oxides of bivalent iron and manganese in the upper horizons of soils, the electrical conductivity (EC) was higher compared to the lower horizons. With increasing depth and getting closer to native materials, lime percentage was increased too. In most profiles due to the higher percentage of organic matter in the surface horizons, cation exchange capacity in the surface horizons was more than the lower horizons. The amount of organic matter was high in the surface horizons because of the less oxidation of plant residues in anaerobic conditions. The most clay minerals were chlorite, smectite, vermiculite, and illite respectively. Palygorskite, kaolinite and mixed minerals had very low content. Chlorite, illite, kaolinite and palygorskite often were inherited. The source of smectite can be also transformation of illite or palygorskite, under waterlogging condition. The puddling condition increased the amount of chlorite in paddy soils. The results showed that the type of clay minerals didn't vary in paddy soils and their relative percentage varied. The waterlogging provid conditions for sustainable of vermiculite in paddy soils. The long term waterlogging condition affected soil quality in this area, and however cultivation rotation suggested.