Oil Palm Sludge as a Source of Soil Fertility


Oil palms are grown in Malaysia and Indonesia primarily. The fruit from an oil palm yields a biofuel that has become a big industry as a vegetable oil. The products have become important export items. After the palm fruit has been pressed to extract all the oil, a bunch of fibers or cake remains. This is the sludge, or more commonly called, the slurry.

The Oil Palm

The oil palm is a tropical tree that can grow 30 feet tall and live a productive life of at least 50 years. The plant has long spear-shaped leaves and a scarred trunk from dropped leaves. Oil palms produce both male and female plants and these in turn produce the large purple fruits, which ripen to orange. The fruit is the money maker on the tree and is a kernel surrounding by pulp. The kernel produces kernel oil and the pulp is the source of the palm oil.


Biofuels are touted as the wave of the future. In an effort to find sustainable fuel sources and reduce dependence on fossil fuels, much effort has gone into research and investigation of alternatives. The sludge that is left over from the process contains organic matter and nutrients which are an excellent organic fertilizer. It contains nitrogen, phosphate and potassium. On plantations much of the sludge is liquefied and sprayed out onto the palm trees as a fertilizer. The result is a perfect recycling system and a money saving practice.


In some countries the financial rewards of growing oil palms have created a problem with the food supply. Rather than grow edibles, farmers are switching to the more profitable oil palm which means there is less food available. Plantation owners are deforesting large areas to expand their palm farms. Even precious peat bogs are being drained to provide land for plantation owners. In an effort to increase yield the oil palm has become a hybrid and the original plant is becoming pushed out of cultivation which could become a dangerous trend and threaten the species.


There are two types of fertilizer made from oil palm sludge. The first is the effluent which is applied as a soil drench. The other is the pressed cake left over after the oil has been extracted. It is sometimes used as animal feed but it has been shown to have an excellent effect on plants when applied as a mulch. The effluent is treated anaerobically which actually increases the nitrogen component. When treatment is finished the effluent is high in all three macro-nutrients for plant growth.


Plantations use the majority of the nutrient rich by-products form palm oil production. The benefits go directly back into the soil from which they came. However, the demand for organic fertilizer in the United States has risen and palm oil sludge has the potential to be an excellent import and fertilizer alternative. The major contents of the fertilizer are water, crude protein, crude lipids, ash, carbohydrates, nitrogen and carotene. It is the list of minerals that is most impressive. The fertilizer contains every major mineral and several minor ones. Palm oil sludge fertilizer is a nutrient rich sustainable organic product.

Keywords: organic fertilizers, palm oil production, palm sludge nutrients

About this Author

Bonnie Grant began writing professionally in 1990. She has been published on Web sites like GardenGuide and eHow. Grant recently earned a Bachelor of Arts in business management with a hospitality focus from South Seattle Community College.