Empty fruit bunch-seaweed biocomposite as potential soil erosion mitigation material for oil palm plantation

Abstract

A composite prepared from oil palm empty fruit bunch (OPEFB) and abundantly available wild seaweed showed great potential as a soil stabilizer, which is attributed to its natural hydrophilic nature. The water absorption and thickness swelling percentages of the oil palm empty fruit bunch-seaweed composite (OPEFB-SW) were recorded at 117.2% (± 7.1) and 10.5% (± 1.7), respectively. The main objective of this study was to determine the effectiveness of the biocomposite in regulating runoff volume and water quality due to soil erosion from the experimental plots. Hence, the volume, turbidity, and total suspended solids (TSS) of the water runoff were investigated. A rainfall simulation test was conducted to test the effectiveness of the cover material (biocomposite) at different application levels (0 kg/m2 (T1), 3.0 kg/m2 (T2), 4.0 kg/m2 (T3), and 5.0 kg/m2 (T4)) of the composite in reducing soil erosion. Overall, the OPEFB-SW composite demonstrated its capability to absorb rainfall impact and therefore stabilize the soil structure. The runoff volume, turbidity, and TSS were reduced significantly to 49.1%, 94.6%, and 99.2%, respectively. In addition, the plot with 4.0 kg/m2 indicates the best treatment in regulating runoff volume, turbidity, and TSS.