2.1. Sampling of Soil
Khewra Salt Mine is the world second largest salt mine, located near
Pind Dadan Khan Tehsil of Jhelum District, Punjab, Pakistan.
Geographically, it is located about 32° 38´ North latitude, 73°10´ East
longitude and an elevation of 313-360 meters above the sea level about
200 km from Islamabad. It has Na+ and
Cl- dominating ions and the pH is near neutral to
slightly alkaline. The sampling area was selected according to land use
and vegetation cover. Vegetation of this area is classified as
sub-tropical dry evergreen forest. Rhizospheric soil samples were
collected by gently removing the plants and obtaining the soil attached
to the roots. For non-rhizospheric saline soil samples, the upper 8-10
cm of mineral soil was collected. At each site, soil samples of
approximately 500 g each from four different locations were collected in
black sterile polythene bags. These samples were stored at 4 ℃ for
further analysis.