Penggunaan Rhizobium Dan Mikrob Pelarut Fosfat (MPF) Untuk Memperbaiki Pertumbuhan Bibit Akasia (Acacia mangium dan Acacia crassicarpa)
Abstract
The increasing of paper raw material requirement is caused by the development of raw material. Therefore, it is needed a method to produce a high quality and quantity of paper. Acacia is one of paper raw material. To increase the growth of acacia seed, an effective usage of Rhizobium and Phosphate Solubilizing Microbe (pSM) seedling inoculant is one of strategies to produce good acacia seeds. The Rhizobium and Phosphate Solubilizing Microbe seedling inoculant can reduce anorganic fertilizer usage and increase the growth of acacia seed. The aims of this research were to select Rhizobium which has an ability to fix atmosphere N2 air and local Phosphate Solubilizing Microbe in dissolving phosphate, also to test the ability of those isolates in increasing the growth of acacia seedling. This research was conducted in the Soil Biotechnology Laboratory, Department of Soil and Land Resource Science, Faculty of Agriculture, Bogor Agricultural University and RAPP greenhouse (Pelalawan and Pangkalan Kerinci R&D Nursary) in Riau. Plant media is cocopit. The experiment consisted of 15 Rhizobium treatments isolated from peat soil, which was planted with A. crassicarpa, and mineral soil, which was planted with A. mangium; 16 Phosphate Solubilizing Microbe treatments taken from peat and mineral soil with 5 replications . The research resulted 2 Rhizobium isolates from IS tested isolates, which could increase the growth of A. crassicarpa effectively, those were Rh Ac S and POS-RIS, and 2 Phosphate Solubilizing Microbe from 16 tested isolates, those were BPF 4 and FPF S. While on A. mangium, there were 2 isolated out of 15 Rhizobium isolates which could increase the A. mangium growth effectively, those were M32-M33-R2N and M45-R2N; also 3 isolates out of 16 Phosphate Solubilizing Microbe, those were M32-BP3, FRK2, and M33-FP2. The characteristic of effectiveness could be seen from the plant height, the amount of leaves, the dry root wight, the dry plant weight, the diameter of bar and the root compactness; so that the usage of Rhizobium inokulan, Rh Ac 5 and P05-RIS equal to the usage of 0.1 kgll Monopotassiumphosphate fertilizer and better than control. Meanwhile the usage of MPF, BPF 4 and FPFS equal to the usage ofO.SI1 kg of Osmocote fertilizer and better than control.