Performance Appraisal of some Exotic Tree Species of Prosopis on Sodic Soil Environment for Fuelwood Production

Performance of eight species of Prosopis was evaluated in species × site interaction trials in order to identify promising species for short rotation energy plantations on sodic soil sites (pH 9.3 to 10.6). Seven of these species (P affinis, P. chilensis, P. fIexuosa, P. glandulosa, P. lampa, P. pallida and P. siliquastrum) were exotic while one (P. juliflora) was a local dominant species. Differences in plant adaptability (survival 43 to 98.7%), height (height 283.7 to 525.7 cm) and diameter (2.08 to 4.67 cm) among different species were highly significantly (P < 0.05, 0.01). Accordingly, basal area (0.77 to 9.44 m² ha^-1) and biomass productivity (1.59 to 29.4 Mg ha^-1) varied greatly among different species. Fuel wood value index (4.14 to 85.42) and usable energy content (31.43 to 559.7 GJ ha^-1) differed greatly among different species. Both the Peruvian species, P. pallida and P. affinis, were identified as the potential species for short rotation (5 years) renewable energy forestry programs on degraded soil sites. Both the selected species were almost similar to local dominant species (P. juliflora) and therefore should be associated with P. juliflora for increasing diversity. Other species, from Chile and Mexico, were significantly inferior (P < 0.05, 0.01) in terms of growth, productivity and energy potential as compared to local dominant (P. juliflora) and Peruvian species. Therefore, P. affinis and P. pallida are recommended for energy resource development on harsh soil conditions as companion species with P. juliflora.