Perpustakaan Digital ITB

Palm oil is a rapidly growing mass-produced good, extracted from the mesocarp and kernel of the oil palm plant (Elaeis guineensis Jacq.). Sustainable land intensification is key to keeping up with this growing demand, minimising environmental impact. This can be done by optimising the plant’s yield. Yield can be affected by the quality of the edaphic properties, the microbial community that inhabits the soil, and the interactions between the two. Functional prediction of the soil microbiome has also become a key tool in studying microbial communities. The purpose of this research is to define the differences in microbial composition, functional characteristics, and edaphic properties between oil palm plantations of low-yield and high-yield in Indonesia’s primary producers: Kalimantan, Sumatra, and Sulawesi. This research will also define the correlation between microbial composition and edaphic properties. 9 samples of secondary soil bacterial 16S rRNA gene amplicon data and edaphic data were extracted from these locations’ oil palm plantation soils, dividing them into groups based on yield and region: high_Kalimantan, high_Sulawesi, low_Kalimantan, and low_Sumatra. 7 out of 9 samples passed quality control by QIIME2-DADA2. Metagenomic and functional profiling of these groups were generated using QIIME2, GenePiper, and QIIME2-PICRUSt2. Principle component analysis (PCA) by XLSTAT and Pearson’s Correlation Matrix by R was performed on edaphic and microbial data. No significant differences in bacterial alpha and beta diversity were found between groups. The high_Sulawesi group showed a significantly higher relative abundance of the beneficial genera Kutzneria, Bradyrhizobium and Actinoallomurus. High-yield groups showed a significantly higher relative abundance of the beneficial genus Nocardioides. The predicted dipeptide permease ATP-binding cassette (Dpp ABC) transporter system was more prevalent in Kalimantan groups. Based on PCA, the order from highest to lowest in value for beneficial edaphic properties was high_Sulawesi, low_Sumatra, high_Kalimantan, and then low_Kalimantan. The opposite was found for potentially negative edaphic properties. Based on the correlation matrix, the relative abundance of Acidicaldus was significantly negatively correlated with silt content and cation exchange capacity (CEC). The relative abundance of Bradyrhizobium, Kutzneria, and Actinoallomurus significantly positively correlated with potential K2O. The relative abundance of Nocardioides was significantly negatively correlated with organic carbon content (OC). It is concluded that groupings based on yield for edaphic properties were not found. Instead, both Kalimantan groups were relatively lower in beneficial edaphic properties and relatively higher in potentially negative edaphic properties, compared to the other groups. High-yield groups had a significantly higher relative abundance of the beneficial genus Nocardioides than low-yield groups. The High_Sulawesi group also had a significantly higher relative abundance of the beneficial genera Kutzneria, Bradyrhizobium, and Actinoallomurus than all other groups. No functional characteristics were found defining plantations based on yield, though the Kalimantan groups are higher in the relative abundance of the Dpp ABC transporter system. The relative abundance of Acidicaldus was significantly negatively correlated with silt content and CEC. The relative abundance of all beneficial genera apart from Nocardioides significantly positively correlated with potential K2O, while the relative abundance of Nocardioides was significantly negatively correlated with OC.