Fertilizer use efficiency of different tree species for higher biomass production.
Greenhouse pot experiments were carried out with 10 (multipurpose) species in which 5-month-old seedlings were planted in loamy soil and treated by application of NPK fertilizer. In the first experiment 0, 50, 100, 150 and 200 p.p.m. N was applied with 100 p.p.m. P2O5 and 50 p.p.m. K2O as basal doses. In the second experiment 0, 50, 100 and 150 p.p.m. P2O5 was applied with 100 p.p.m. N and 50 p.p.m. K2O as basal doses, and in the third 0, 25, 50 and 75 p.p.m. K2O was applied with 100 p.p.m. each of N and P as basal doses. N was applied in split doses before and 1 and 2 months after transplanting, and P and K were applied before transplanting. Biomass measurements of seedlings were made after 6 months. Eucalyptus camaldulensis, E. citriodora and Acacia nilotica responded to N, P and K, Acacia catechu, E. grandis, E. tereticornis 'FRI-5', and Prosopis juliflora only to N and P, and Albizia lebbeck [A. lebbek], Leucaena leucocephala (var. K8) and E. tereticornis 'FRI-4' to N and K only. In the absence of other fertilizers, and at 50 p.p.m. N, nitrogen use efficiency was greatest in E. camaldulensis, followed by E. grandis, E. tereticornis (both varieties), Acacia nilotica and E. citriodora; other species had much lower values; trends were similar for other N dosages. Phosphorus use efficiency (in the absence of other fertilizers) was greatest in Acacia catechu, followed by E. tereticornis 'FRI-5', E. citriodora, Albizia lebbek and Acacia nilotica, but varied between dosages; other species were not very efficient. Potassium use efficiency (in the absence of other fertilizers) was greatest in Albizia lebbek, followed by E. camaldulensis, Acacia nilotica, L. leucocephala, E. tereticornis 'FRI-4', Acacia catechu, E. citriodora and P. juliflora, but varied between dosages. Variations in specific (i.e. N, P or K) fertilizer use efficiency in the presence of other fertilizers are discussed.