The dynamics of functional microbes population in two depths under raru (Cotylelobium spp) stand

Abstract

Raru (Cotylelobium spp) is one of the endemic plants in North Sumatra from the Dipterocarpaceae family. Plant growth is strongly influenced by the condition of the soil environment. Soil provides nutrients to increase plant growth. Soil also a habitat for various microbes that affect plant growth. This study aimed to calculate functional microbial populations under raru stands such as arbuscular mycorrhizal fungi, phosphate solubilizing microbes, and cellulose decomposer microbes. The measurement of the population use plate count methods. Soil samples were taken in composite with 0-5 cm and 5-20 cm in the raru pulut, raru dahanon and raru songal rhizosphere area in Bona Lumban Village, Tukka District, Central Tapanuli Regency North Sumatra. The result showed that a functional microbial population was calculated higher at a depth of 0-5 cm compared to a depth of 5-20 cm. The microbial population of phosphate solubilizing microbes ranged from 10.12x 103 to 92.44x103 CFU mL−1 with the largest population found in the raru songal rhizosphere. Cellulose decomposer microbial populations ranged from 6.21x103 to 21.55x103 CFU mL-1 with the highest population found in the raru pulut rhizosphere. The highest arbuscular mycorrhizal fungi density in raru dahanon rhizosphere.