Comparative assessment of soil properties under commercial tree plantations

Abstract

Bulk and rhizosphere soils were collected from tree plantations viz., Acacia leucophloea, Melia dubia and Pongamia pinnata. Among the tree plantations, A. leucophloea recorded the lowest pH. The lowest electrical conductivity of 0.21 dSm-1 and bulk density value of 1.05 Mg m-3 was recorded under pungam plantation indicating higher uptake of soluble salts. The water soluble carbon content of bulk and rhizosphere soils were the highest in P. pinnata plantation. The highest value of soil microbial biomass carbon was registered under A. leucophloea plantation. In the rhizosphere soil C: N ratio of 25.11 was recorded in pungam plantation indicating the highest C content in rhizosphere of pungam plantation. The rhizospheres of P. pinnata plantation accumulated higher water soluble carbon and hence supported higher microbial biomass. The results imply that fast growing M. dubia and leguminous N fixing P. pinnata plantations could be recommended for restoration of degraded lands for enhancing soil quality.