Study on soil physico-chemical attributes under Pinus roxburghii Sargent along elevational gradient in Solan Forest Division of Himachal Pradesh

The present study was conducted at elevation ranges from 900 m to 2100 m in the year 2012–2013 in Solan Forest Division of Himachal Pradesh. The physico-chemical characteristics of soils along elevational classes showed that the values of bulk density increased with increase in elevation from 900–1200 m to 1800–2100 m. There was a decrease in per cent organic carbon with increase in soil depth at all the elevations. The soil organic carbon decreased with increase in elevation with minimum of 0.24 per cent at 1800–2100 m and maximum of 2.63 per cent at 900–1200 m elevation. Overall pH values varying from 6.00 to 6.90 showed an increasing trend with soil depth. The perusal of data indicates that in general pH varied from 6.00 at 900–1200 m elevation to 6.9 at 1800–2100 m denoting less variation in pH in the study area. Available nitrogen varied from 271.33 kg/ha (20–40 cm) to 533.20 kg/ha (10–20 cm) at 900–1200 m elevation and showed a decreasing trend with increasing depth. Available phosphorus varied from 8.90 (20–40 cm) to 34.5 (10–20 cm) at elevation of 12001500 m and showed a decreasing trend from 10–20 cm to 20–40 cm depth as in case of per cent organic carbon and available nitrogen. Available potassium showed an increasing trend with increase in soil depth at all elevations.