Comparative Assessment of Soil Quality at the Defence Establishments

Abstract

The present study was carried out to adjudge the soil quality of two sites at the defence establishments in India. Various soil samples were collected from the surface and up to 20 cm depth (subsurface) as per apportioned gridding method. These samples were subjected to air drying for 15 days and were characterised for various parameters. The soil is clayey and loamy with granular blocky structure on both the sites.  The pH ranged from 7.1 to 7.72 0.1 for site I and from 5.5 to 8.0 f 0.1 for site 11; salinity and bulk density ranged from 0.1 per cent to 8 per cent and from 1.2 glcm3 to 1.5 g/cm3, respectively and soil moisture was about 0.4 f 1 per cent for both the sites. Similarly, total Kjeldahl nitrogen ranged from 1100 mg kg-' to 1900 mg kg-' for site I and 1700 mg kg-' to 9000 mg kg ' for site I1 and total organic carbon ranged from 18 mg g-' to 75 mg g ' for both the sites. A good correlation between nitrate concentration and various explosive process activities has been observed which gives substantial evidence in terms of contamination of the soil. High performance liquid chromatography analysis, which shows varied concentrations of RDX-HMX, NB, DNB, DNT, and TNT in the respective ranges 0.003-2.300 rng g-1, 0.002-0.350 mg g~1, 0.002-0.550 mg g-1, 0.004-0.041 mg g-1 and 0.010- 0.050 mg g-1 for site 1 and 0.002 - 0.013 mg g-1, 0.005 - 0.350 mg g-1, 0.003 - 0.080 mg g-1, 0.001- 0.100 mg g-1, 0.0001- 0.044 mg g ~a1n d 6*10-6- 0.080 mg g-1 for sites I1 has also indicated the contamination of soil by nitro-organics. These results serve as a valuable database for an ongoing project on the development of phytoremediation technology to detoxify such sites.