EFFECTS OF ARBUSCULAR MYCORRHIZAL INOCULATION AND FERTILISATION ON THE GROWTH OF ACACIA MANGIUM SEEDLINGS

Acacia mangium is a popular species for forest plantation and is widely used for the production of furniture, particleboard, pulp and paper and wood chips. Proper fertilisation and soil enhancement will further increase its growth and yield for sustainable forest plantation. Arbuscular mycorrhizas (AM) and fertilisation have shown promising results in increasing plant growth and biomass through increased nutrient uptake. However, the combined use of AM inoculation and fertilisation in fastgrowing species such as A. mangium needs to be further assessed. The effects of the treatment on the growth of A. mangium seedlings, chemical contents of the growth media and shoot nutrient concentrations were investigated. Pot trials of uninoculated control without fertilisation (control), uninoculated with fertilisation (+NPK), inoculated without fertilisation (+AM) and inoculated with fertilisation (+AM+NPK) were laid out in a complete randomised design. Seedling growth was monitored for three months in the nursery. Shoot height, stem diameter and number of phyllodes were recorded monthly. Root and shoot biomass, root:shoot ratio, mycorrhizal infection rates, nutrient concentrations in media and shoot were determined at the end of the experiment. Treatments with +NPK and +AM+NPK significantly increased plant growth and media nutrient contents of A. mangium seedlings. Shoot nutrient concentrations of +AM fungi were relatively increased with inoculation.