Author : Ignatius Muhadiono

Summary : Seedlings of Albizia procera (Roxb) Benth, a native species of the ASEAN region were grown under screenhouse condition for three months (Studies I and II) and four months (study III). The effects of soil types, chemical fertilizer, and biofertilizer application on seedling growth were studied. The parameters were height, diameter, nodule number, dry weight, top/root ratio, total dry matter yields, N contnet, N uptake, /\ N uptake, P content, P uptake, and /\ P uptake. The effect of nitrogen fertilizer application was significant on height, diameter, N content, and /\ N uptake. Inoculation with Rhizobium yielded significant effect on height at 90 DAP (days after planting), diameter at 60 and 90 DAP; N content and /\ N uptake. The N content was 20.7 percent better in the inoculated and fertilized with the 100 kg N/ha rate than the uninoculated and fertilized with the same rate. The interaction effect between soil and N fertilizer was significant on height (90 DAP), diameter (30 and 90 DAP) and N content, while the interaction effect between soil and Rhizobium inoculation was shown to be significant on height (60 DAP), diameter (60 and 90 DAP), nodule number, total dry matter yield, and N content. The interaction effect between N fertilizer and Rhizobium inoculation was significant on height (60 and 90 DAP), diameter from 30 up to 90 DAP, and N content. Significant interaction effects among three factors-- soil, nitrogen and Rhizobium inoculation-- was observed on height (60 and 90 DAP), diameter (60 DAP), and N content. The amount of nitrogen replaced by Rhizobium inoculation was estimated to be 82.5 kg N/ha of chemical nitrogen fertilizer. Phosphorus application improved height and diameter growth, nodule number and dry matter production of A. procera (60 and 90 DAP). Phosphorus application also significantly improved P content, P uptake and /\ P uptake of A. procera. Inoculation with Glomus etunicatum also favorably enhanced height and diameter (30 and 60 DAP and P content.