ABSTRACT
The rapid growth in oil palm production has raised environmental concerns due to the massive discharge of liquid and solid waste. To address this issue, waste generated need to be optimized by composting and converting the waste into organic fertilizer. The practice of pure inorganic fertilization must also be discontinued due to the rising cost of imported fertilizers and their detrimental effect on the soil. Furthermore, several studies have established that recycling self-produced organic waste as fertilizer is an excellent method to achieve sustainability. Therefore, this study investigates a significant response to organic fertilization treatment. The bioorganic empty fruit bunch (EFB) compost was tested on Podzols soil (Typic Placorthods) in the nursery and in the young mature stage of the palm that was treated from the beginning of planting. The results showed that organic fertilization using low and high concentrations of fresh and composted EFB had a more significant effect on seedling growth. A high dose of composted EFB positively affected the N and K content of the leaf. Composted EFB had added value, especially in improving soil chemical properties and assimilation of N nutrients by oil palm seedlings, especially Podzols (Typic Placorthods). Pure inorganic fertilization on Podzols (Typic Placorthods) could not have been more practical due to inadequate nutrient uptake. Composted EFB had a positive effect superior that of the fresh EFB on the chemical composition of the soil, such as improving the saturation rate of the cation exchange capacity and the exchangeable K and Mg. Fresh EFB was good, but composted EFB was better for maintaining yield and less attractivity to Oryctes, which is essential in replanting.
ABSTRACT
Palm oil production has increased significantly, specifically in Indonesia and Malaysia. However, this growth has raised environmental concerns due to the high discharge of empty fruit bunches, palm oil mill effluents, and other solid wastes. Therefore, this study aims to examine the treatment of palm oil waste by composting and systematically review insights into its application through a systematic literature review approach. Among the 1155 articles, a total of 135 were selected for a systematic review of palm oil waste management developments and their applications, while 14 were used for determining compost quality according to the criteria and requirements established in the systematic literature review. Moreover, using Egger's test, JAMOVI 1.6.23 software was used to analyze random effects models with 95% confidence intervals and publication bias. The results showed that palm oil waste was optimally treated by composting, which is considered as a sustainable technology for protecting the environment, human safety, and economic value. The in-vessel method with a controlled composting chamber is the best system with a minimum time of 14 days. However, it requires tight control and provides a final product with a high microbial colony form outdoors and indoors compared to the windrow system. This study is useful to see the bias of research results and helps to find new studies that need to be developed, especially in this case related to the management of palm oil waste into organic compost fertilizer and its application methods in the field. It is suggested that applying palm oil waste or compost is mainly performed by mulching. In contrast, new challenges for better processing to produce organic fertilizers and applicable technologies for sustainable waste management are recommended. The method must be affordable, efficient, and practical, combining compost quality with maximum nutrient recovery.
Subject(s)
Composting , Waste Management , Humans , Palm Oil , Soil , Waste Management/methods , Fertilizers/analysisABSTRACT
Salinity is one of the most damaging abiotic stresses due to climate change impacts that affect the growth and yield of crops, especially in lowland rice fields and coastal areas. This research aimed to isolate potential halotolerant plant growth-promoting rhizobacteria from different rhizo-microbiome and use them as effective bioinoculants to improve rice growth under salinity stress conditions. Bioassay using rice seedlings was performed in a randomized block design consisting of 16 treatments (control and 15 bacterial isolates) with three replications. Results revealed that isolates S3, S5, and S6 gave higher shoot height, root length, and plant dry weight compared with control (without isolates). Based on molecular characteristics, isolates S3 and S5 were identified as Pseudomonas stutzeri and Klebsiella pneumonia. These isolates were able to promote rice growth under salinity stress conditions as halotolerant plant growth-promoting rhizobacteria. These three potent isolates were found to produce indole-3-acetic acid and nitrogenase.
