Abstract

Sandy loam surface soil from the Peechi campus of KFRI, Kerala, was used in pot experiments with seedlings of teak (Tectona grandis), eucalypt (Eucalyptus tereticornis) and albizia (Paraserianthes [Albizia] falcataria). Soil samples in concrete pots (34X25 cm) were compacted to 3 bulk densities (1.1, 1.4 and 1.6 g/cm3) which corresponded to maximum water holding capacities of 27, 16 and 14, respectively. Six-month-old polypot seedlings of the 3 species were transplanted to the pots and grown for 6 months, when they were harvested and measurements made of root and shoot length and biomass, and number of leaves and internodal length. Root length in teak and eucalypt seedlings was significantly reduced at soil densities of 1.4 and 1.6 g/cm3, while foralbizia significant reduction occurred only at 1.6 g/cm3. Root biomass was significantly reduced only at a soil density of 1.6 g/cm3, for all species. Shoot length of teak was not significantly affected by treatments (shoot growth was less in this species than in the other two), while shoot biomass (which was greater than in the other two species) was slightly higher at soil density 1.4 g/cm3 than at 1.1 g/cm3, but was reduced at 1.6 g/cm3. For eucalypts and albizia, shoot length and biomass were significantly reduced only at 1.6 g/cm3 soil density (with albizia, like teak, showing slightly greater biomass at 1.4 g/cm3 soil density than at 1.1 g/cm3). Leaf numbers were significantly less at the highest soil density only for eucalypts and albizia, with no significant differences between treatments for teak (which had fewer leaves than the other two species). Internodal length showed no significant difference between treatments for albizia and eucalypts but was significantly less at 1.6 g/cm3 soil density in teak. The importance of reducing soil density for successful plantation establishment is emphasized