Author : Yadi Setiadi

Summary : Two studies were conducted to test the effectivity of four rhizobium isolates on Moluccan sau (Albizia falcataria). In study I, three provenances were inoculated and grown in three soil types. In study II, varying urea and lime levels were applied to Luisiana soil to grow the West Java (Indonesia) provenance inoculated with the subject isolates: A (subscript 14) and A (subscript 18) (Makiling) and Alfa (subscript 1) and Alfa (subscript 2) (Mindoro), with basal application of 90 kg/ha of P(subscript 2) O (subscript 5) and 60 kg/ha K (subscript 2) . Both studies were set up with split-split plot design in complete randomized design (CRD) and were harvested four months after sowing. To evaluate the responses, height, diameter, total biomass, root/shoot ratio, nodulation, nitrogen (N) content, and N uptake were used as the parameters. Results showed that in both studies, the inoculated seedlings were generally more vigorous and greener than the uninoculated ones. The Alfa (subscript 2) isolate performed the best without soil amendments, while Alfa (subscript 1) was the best isolate in Luisiana soil with N-fertilization and calcium carbonate (CaCo(subscript 3)) application. Consistently, the second-best performing isolate in both studies was A (subscript 14). The West Java provenance gave significantly higher values in terms of seedling growth than either Palawan or Bislig provenance. Luisiana (sandy clay loam) grow the best seedlings compared to Puting Lupa or Carranglan soil (both clay loam). The combination of the highest time level (0.4840 g CaCO (subscript 3)) and the lowest urea level (0.25 g) yielded the tallest seedlings.