Long-term application of organic matter improves soil properties and plant growth-promoting bacteria in soil communities of oil palm plantation

ABSTRACT

Oil palm (Elaeis guineensis) is a major contributor to global vegetable oil production; however, ensuring its sustainability remains a critical challenge, particularly concerning soil health. In this study, we investigated the impact of long-term organic matter application as part of good soil management (GSM) practices on oil palm plantations and compared it with poor soil management practices to determine the presence of plant growth-promoting bacteria (PGPB) in soil communities. The ten-years regular application of organic matter to the soil in the GSM plots led to notable improvements in soil chemical properties, including total organic carbon, total nitrogen, available phosphorus, available potassium, and cation exchange capacity. Metagenomic analysis revealed a significantly higher abundance of beneficial microbial species exclusively found in GSM plots, supporting oil palm growth. Furthermore, a novel finding emerged from this study, as it successfully predicted the metabolic function of PGPB in soil communities using PICRUST2 provided by the soil microbiome. PICRUST2 analysis indicated that the long-term application of organic matter in GSM plots increased functional enzymes related to PGP activities, such as nitrogen fixation, phosphate solubilization, potassium solubilization, and phytohormone synthesis. This study underscores the significance of implementing GSM practices in oil palm plantations by incorporating eco-friendly materials, such as organic matter, to enhance soil health and fertility and ensure oil palm sustainability.

KEY WORDS:

• Beneficial microbes
• long-term organic matter application
• microbial community
• oil palm plantation
• sustainability

Acknowledgments

This work was partly supported by JSPS KAKENHI Grant-in-Aid for Scientific Research (B) [JP 23H03595]. We acknowledge Indonesian Oil Palm Research Institute (IOPRI) for providing the samples (administration and sample collection). We also would like to acknowledge Faculty of Agriculture, Gadjah Mada University (UGM) as the counterpart of this research and the Center for Advanced Instrumental and Educational Supports, the Faculty of Agriculture, Kyushu University for their support with MiSeq. This work was supported partly by Japanese Government Monbukagakusho (Ministry of Education, Culture, Sports, Science, and Technology, MEXT) scholarship.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Abbreviations

AK, available potassium; AP, available phosphorus; ASV, amplicon sequence variant; CEC, cation exchange capacity; EFB, empty fruit bunches; GSM, good soil management; IAA, indole-acetic acid; ITS, internal transcribed spacer region; PGPB, plant growth-promoting bacteria; PICRUSt2, phylogenetic investigation of communities by reconstruction of unobserved state 2; PSM, poor soil management; TN, total nitrogen; TOC, total organic carbon.

CRediT authorship contribution statement

Fandi Hidayat: Conceptualization, Methodology, Investigation, Writing-original draft. Rizki Desika Putri Pane: Data curation, Resources, Formal analysis. Fadilla Sapalina: Data curation, Resources, Formal analysis. Eka Listia: Data curation, Resources, Formal Analysis. Tomonori Koga: Formal analysis, Software. Winarna: Project administration, Validation, Supervision. M. Edwin Syahputra Lubis: Project administration, Validation, Supervision. Mugihito Oshiro: Conceptualization, Writing – review & editing. Kenji Sakai: Conceptualization, Writing – review & editing. Sri Nuryani Hidayah Utami: Validation, Supervision. Yukihiro Tashiro: Conceptualization, Supervision, Methodology, Validation, Writing – review & editing.

Additional information

Funding

This work was partly supported by JSPS KAKENHI Grant-in-Aid for Scientific Research (B) [JP 23H03595].