An assessment of Haloxylon succession on some physical and chemical characteristics and erodibility indices in Taybad sandy lands, Khorasan province, Iran

ABSTRACT: Mobile sand is the biggest obstacle to sustainable development in arid and semi-arid regions of Iran. The most effective way to maintain and promote sustainable development is reform and recovery of vegetation in these areas. Mobile sand stabilization has been greatly influenced on soil conservation and minimizes erosion in Taybad. Regarding to existence of reclaimed sandy lands which is caused by the Haloxylon sequence, the rate of change on physical and chemical characteristics and soil erodibility indices were studied in the area. For this purpose, five sites were selected based on Haloxylon age (41, 28, 19 and 11 years old and a control site (no Haloxylon plantation). Considering planting age Haloxylon, the results represents a 24, 14 and 8% reduction, respectively in sand, silt and clay contents. bulk density was reduced from 1.57 to 1.37 g/cm. Maximum weighted average diameter (2.48 mm) was belonging to 41 years old-Haloxylon plantation while minimum value (0.85 mm) was observed in control site (without any plantation program). Moreover, highest amount of acidity (8.4) was observed in the 41 years old-Haloxylon plantation and lowest pH (7.4) was measured in control site. The oldest Haloxylon plantation (41 years old) caused maximum amount of electrical conductivity (EC) (0.7 ms/cm) and the lowest value of EC (0.33 ms/cm) caused by control treatment. The amount of Caco3, C and N respectively increased by %0/6, %0/24 and %0/02 from control to 41-years-old site . The results showed that many of soil physico-chemical properties were improved as Haloxylon afforestations became older.