Effects of the super absorbent polymer (SAP) were tested on both the soil attributes and growth properties of Seidlitzia rosmarinus in the arid Emrani region of Iran in a reclamation study. A SAP concentration gradient (SAP 0 ¼ SAP 0 g dm À3 , SAP 1 ¼ SAP 1 g dm À3 , and SAP 3 ¼ SAP 3 g dm À3 of soil) was coupled with 30-and 60-day irrigation intervals, and results were evaluated after two growing seasons. Results indicate that application of SAP 1 increased available water content up to 68.5% and decreased soil bulk density by 25.5% and soil infiltration rate by 21.5%. SAP enhanced growth indices and seedling establishment rates of S. rosmarinus under drought stress. In addition, the application of SAP 3 can significantly increased soil cation exchange capacity up to 31% compared to the control. This study demonstrated the increased water retention properties of SAP that leads to higher soil water storage capacity for S. rosmarinus seedlings during the first months of out-planting in arid regions. Overall, the used SAP enhanced soil and plant properties, but most assessed parameters did not differ between SAPs 1 and 3. Therefore, the 1 g application rate is recommended based on technical as well as economic considerations.

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Minimizing the impact of timber harvesting on forest stands and soils is one of the main goals of sustainable forest operation (SFO). Thus, it is necessary to make an accurate assessment of forest operations on soil that is based on the SFO perspective. The present study was conducted according to SFO principles to investigate the time required for the natural recovery of soil after disturbance by skidding operations in some Iranian forests. The physical, chemical, and biological properties of soil found in abandoned skid trails from different time periods were compared with undisturbed forest soils. The soil bulk density, the penetration resistance, and the microporosity of a 25-year-old skid trail were 8.4–27.4% and 50.4% greater, and the total porosity, macroporosity, and soil moisture were 1.9–17.1% and 4.6% lower than the undisturbed area. In a 25-year-old skid trail, the values of pH, Electrical conductivity (EC), C, N, available P, K, Ca, and Mg, earthworm density, and biomass were lower than in the undisturbed area, and the C/N ratio value was higher than in the undisturbed area. High traffic intensity and slope classes of 20–30% in a three-year-old skid trail had the greatest impact on soil properties. In order to have sustainable timber production, SFO should be developed and soil recovery time should be reduced through post-harvest management operation.

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