Soil physico-chemical and biological properties as affected by vegetation systems and elevation in western Himalayas

Assessment of various soil properties is vital for understanding and predicting long term effects of changes in land use and climate. A total of 414 composite soil samples (0–30 cm) were collected from different vegetation systems i.e. agriculture based agroforestry system (ABAF), chir pine silvipasture (SPCP), mixed-trees silvipasture (SPM), ban oak silvipasture (SPBO) and grassland (Gr) at different elevations (500–1850 m) in Solan district, Himachal Pradesh, India for examining various soil properties. All the tested soil parameters varied significantly (P<0.005) among the vegetationsystems and they increased along the elevation except for pH, EC and bulk density. Maximum organic carbon, moisture content, bacterial, fungal and actinomycetes count (2.10%, 19.43%, 104.28 x 10⁶ cfug⁻¹, 63.59 x 10³ cfug⁻¹ and 65.07 x 10⁴ cfug⁻¹, respectively) were recorded in SPBO and minimum in grassland (1.68%, 8.03%, 38.52 x 10⁶ cfug⁻¹, 24.69 x 10³ cfug⁻¹, 19.51 x 10³ cfug⁻¹, respectively). While maximum pH (6.95), EC (0.107 dSm⁻¹) and bulk density (1.37 gcm⁻³) were recorded in ABAF, SPM and grassland system, respectively and their respective lowest values were recorded in SPBO, grassland, ABAF as 6.30, 0.094 dSm⁻¹ and 1.14 gcm⁻³. Thus the tree-based systems revealed better soil properties compared to grassland in all the elevation zones.