Evaluation of soil physical quality in dominant series of calcareous soils in south-west of Iran

Calcareous soils are widely spread in arid and semiarid regions. Carbonates can affect soil quality by influencing soil pH, structure and soil available water. There are lots of calcareous soils in Iran and especially Khuzestan province, so, providing sustainable agriculture evaluating the soil quality is essential. This study was done to evaluate the soil physical quality in dominant calcareous soil series in Khuzestan province, Iran. Soil physical quality indicators, including Dexter's S index, air capacity, soil available water capacity, relative water capacity and macroporosity were calculated. The results showed that, based on Dexter's S index, only one calcareous soil series had a poor physical quality (S < 0.035). However, the simultaneous evaluation of different soil quality indicators showed that 56 % and 22 % of studied calcareous soil series had limited aeration and soil available water, respectively. While the weakest soil physical quality was related to the southeastern soil of Ahvaz, with both aeration and soil available water limitations. The results showed that the proper assessment of soil physical quality in calcareous soils requires considering more physical indicators than just Dexter's S index related to soil aeration condition including air capacity and macroporosity.