The use of composted oil palm wastes in the oil palm nursery as an organic component of growing medium for oil palm seedlings seems promising in sustainable oil palm seedling production. This study was conducted to investigate the effects of six oil palm waste compost rates (0, 20, 40, 60, 80, and 100%) on the growth performance of oil palm seedling and nutrient uptake in the prenursery stage (0–3 months). The addition of oil palm compost reduced the soil bulk density (1.32 to 0.53 g cm−3) and increased soil pH (4.7 to 5.1) of growth media. Oil palm waste compost treatment produced positive growth performance up to 70%. A regression analysis indicated in 72% of compost and topsoil mixture as a polybag growth medium was optimum in producing best growth performance of oil palm seedling in the prenursery stage. Foliar analysis implied highest nutrients uptake (N, P, K, Mg, Ca, Fe, Zn, and Cu) for seedlings grown in 60 to 100% compost media.

Applying a mulch of oil palm empty fruit bunches (EFBs) from processing mills to newly transplanted oil palm is widely practiced for sustainable management and recycling of solid waste from the oil palm industry. Thus, it is important to understand the decomposition and mass loss of EFBs and its nutrient release pattern for better fertility management. The present study was conducted in a newly transplanted oil palm field to investigate the mass loss of applied EFBs and nutrient release pattern over a 12-month period. The treatments evaluated in the present study were: (1) chemical fertiliser (CF) application only; (2) EFB application only; and (3) EFB and CF application (EFB+CF). The treatments were applied immediately after transplanting 13-month-old palms. EFBs were applied around the base of the oil palm at a rate of 170 kg palm–1. Results showed that 50% dry weight of EFB and EFB+CF was lost within 90 days of application. The C : N ratio decreased from 82 to 20 after 180 and 172 days in EFB and EFB+CF respectively. The breakdown of lignin in EFBs was found to be significantly accelerated by the introduction of CF. Soil properties were improved by EFB application with an increase in pH, total mineral N and exchangeable K of the top soil. After 317 DAP, the soil organic C content subjected to treatment with EFB only and EFB+CF was significantly higher (i.e. 1.7%) when compared with that subjected to the control treatment (i.e., 1.3%). Total N increased significantly from 0.06% to 0.12% for both EFB treatments.

Emerging investigations have indicated that many plant polysaccharides may be beneficial in treating metabolic diseases. Hitherto, the therapeutic efficacies and the potential toxicity of polysaccharides extracted from Clinacanthus nutans (C. nutans) remains unexplored. This investigation studied on the in-vivo acute and sub-acute oral toxicological profile of the highest doses of C. nutans bioactive polysaccharides (CNBP) extracted from leaves using conventional toxicity methods. 39 healthy 8-10 weeks male Sprague-Dawley rats (n=3), were randomly assigned into: control, acute and sub-acute groups receiving 125, 250, 500, 1000, 2000, and 3000 mg/kg/day of CNBP extract respectively; acute groups received a single dose of CNBP extract; whereas the sub-acute groups received daily single doses of CNBP extract for 14 days. Oral administration of up to 3000 mg/kg of CNBP extract caused no abnormal toxicity signs during the 14 days. However, daily administration of 500 mg/kg or higher doses of CNBP extract for 14 days induced a mild degree of toxicity in the liver characterized by elevated alkaline phosphatase levels. The CNBP extracts exhibit therapeutic potential, exemplified by diuretic, natriuretic, anti-hypertensive, anti-tachycardia, reno-protective, and cholesterol lowering properties. Precaution should be taken when administrating the extracts at higher doses and longer durations.