The oil palm tree that is found in Malaysia is known as the ‘African Oil Palm’ to distinguish it from the ‘South American Oil Palm’ and is widely grown in countries such as Malaysia, Indonesia and some African countries.

The mature palm is made up of roots, trunk and the foliage. The roots which are made up of lateral roots provide good anchorage and also become an effective absorbing system for water and inorganic nutrients. There is a tendency for the roots to grow towards sources of nutrients such as rotten stumps and also the decomposing fronds that are placed in the inter rows of the oil palm trees. They also grow towards the source of water found in the soil.

As is common with other palms, the trunk is made up of a mass of vascular bundles and enclosed by tissues. In the first one or two years of the growth of the oil palm tree, thickening growth appears to be seen giving a broad base to the trunk which can grow to a diameter of about 60 cm and as the trunk elongates, it is usually about 40 cm in diameter. The trunk is completely enclosed by the fronds which can start to fall of the trunk when the palm reaches more than 10 years and continue falling until the life span of the palm. The trunk can grow to a height of about 15 to 18 meters and the average elongation of about 45 cm, can occur annually and in certain circumstances can go up to 1 m if the growth condition is very favourable. There are palm trees that may grow up to sixty feet and more in height. The trunks of young and adult plants are wrapped in fronds which give them a rather rough appearance. The older trees have smoother trunks apart from the scars left by the fronds which have withered and fallen off.  The vascular tissues found in the trunk provides both mechanical support and as a conduit for the transportation of nutrients to the other parts of the palm. Apart from that they support the leaves and also functions as a storage organ. The trunk produces between forty to sixty fronds and on the average produces between two to three fronds per month.

The fronds are arranged in the form of two spirals on the stem and are generally known as the ‘right handed’ arrangement in which the spiral runs form a high right to a low left position and in a smaller number of palms known as the ‘left handed’ arrangement where spiral runs form high left to a low right position. Each mature frond comprises of a rachis, pinnae and spines. The rachis is broad at the base and narrows as it moves away from the base of attachment to the palm.  The frond length varies according to the location of the palm and can grow to a length of about 9m. The pinnae which are made of between 200 – 400 per frond are made up of two rows on both sides of the rachis and those found in the middle region to be much longer. Those that grow near the frond base are smaller in number and form strong spine like structures. Each pinnae is made up of a midrib with laminar tissues on both sides. The intensity of the formation of the leaves depend on the intensity of the sunlight reaching the canopy.

Each tree produces compact bunches weighing between 10 and 25 kilograms with 1000 to 3000 fruitlets per bunch. Each fruitlet is almost spherical or elongated in shape. Generally the fruitlet is dark purple, almost black and the colour turns to orange red when ripe. When the fruitlet turns orange in colour, these are indications that the fruitlet is ripe enough to be harvested. Each fruitlet consists of a hard kernel (seed) inside a shell (endocarp) which is surrounded by a fleshy mesocarp.

A normal oil palm tree will start bearing fruits after 30 months of planting and will continue to be productive for the next 20 to 30 years thus ensuring a consistent supply fruits for the extraction of oil. Normally the trees are replanted when they reach the age of 25 years as the height of the palms make it difficult for the harvesters to harvest the bunches. Apart from that there is a need to introduce better planting materials which could produce better yield and are disease resistant in place of the aging palms which may not have the above mentioned factors that are achieved due to continuous breeding programmes by the industry players. 
 
As mentioned above, the oil palm tree produces abundant leaves which help to build a good canopy cover. The good canopy cover enables rain droplets to be trapped among the fronds before they drop on to the ground. The trapping of the rain droplets helps to cushion the intensity of the rain droplet and slow their speed before they fall to the ground thus causing minimum disruption to the soil surface. The cushioning effect enables very little erosion to occur on the surface of the soil particularly on the top soil found under the palms. In addition if vegetation are found on the soil, there is practically no erosion of the top soil found under the palm.

As part of eco-conscious planting habits, planters have always been reminded not to leave the planting rows bare as it could cause erosion. Maintaining soft grasses and other type of grasses help to prevent erosion occurring. Erosion also destroys the thousand of microorganisms that are found in the top soil particularly below the dead foliages found under the palms. Not only are they swept away, but also the microorganisms that flourish under these foliages are exposed and could also be swept along.

The soil represents a favorable habitat for microorganisms and is inhabited by a wide range of microorganisms including bacteria, fungi, algae, viruses and protozoa. Microorganisms are found in large numbers in soil; usually between one and ten million microorganisms are present in per gram of soil and with bacteria and fungi being the most prevalent. Apart from that, soil organisms are very important as almost every chemical action and reaction that takes place in oil involves active contributions from soil microorganisms. They play an active role in enhancing soil fertility by getting involved in the recycling of nutrients such as carbon and nitrogen which is essential for plant growth. There are also soil microorganisms that contribute to the decomposition of the organic matter entering the soil which results in the recycling of these into nutrients. For example nitrogen fixing bacteria can transform nitrogen gas present in the soil into soluble nitrate compounds which enrich the soil and to be absorbed and used by the palm.

Other soil microorganisms are found to produce hormones that can improve plant health and contribute towards higher yield. Microorganisms are influenced by the nature, properties and arrangement of soil particles and they also modify these particles and their arrangements. Thus disruption that occurs to the soil surface in the form of erosion of the top soil also affects the growth of these microorganisms. In soils, microbial life is also indirectly influenced by surface interactions as molecules that are involved in microbial activity can absorb soil particles. Some microorganisms also burrow and churn up the soil and this improves soil structure and aggregation while others have the ability to break down resistant organic matter such as lignin, toxins and pesticides. They do also have the ability to protect plants from antagonistic pathogens while some can dissolve minerals and provide nutrients in dissolved mineral form to plants.

Apart from microorganisms, there are also earthworms that incorporate dead organic matters into the soil, ingest, excrete the nutrient rich casts in the soil and help to improve aeration, water infiltration, drainage, and also enhance nutrient availability and cycling. These microorganisms and earthworms which enrich the soil can be destroyed by intensive erosion. 

Thus the canopies play a vital role in maintaining the growth of microorganisms in the process of preventing erosion. The other role the canopies play is to maintain a cool temperature of the area beneath the canopy. Generally the temperature beneath the canopy is very much lower than that above due to the filtration of the light through the canopy. This helps to reduce the temperature of the soil beneath the palms and maintains moisture in the soil. The moisture help in maintaining the microorganisms found in the soil and provides the much needed moisture for the soft grasses and the cover crops to sustain. The cool atmosphere also enables soft grasses and cover crops flourish under the palms.

The trunks are another component of the oil palm tree that have great use after they have been replaced during the process of replanting. Previously the trunks were burnt before replanting and this have caused severe environmental problems. With the zero burning policies being strictly implemented by palm oil plantation companies in Malaysia, the trunks have to be eliminated using a different approach. The trunks are felled first and then chipped in sizes not more than 10 cm and then transported to trenches which are dug at the fourth palm row. If the trunks are shredded, they are normally stacked at the second palm row in the field. In the case of contour planting, the shredded palms are spread in the inter rows and left to rot. 

Trunks of mature palms that have been chipped or shredded can be recycled more effectively. They contain up to 1,000 kilograms per hectare of potassium. Exposure to the sun and rain gives a slow breakdown of the material which subsequently turn into natural fertilizer. Chipping or shredding releases all the nutrients within 2-3 years and are fully absorbed by the plants and palms planted in the rows and inter rows. The trunks of palm trees can also be used as lumber or made into fiberboards. There are companies that have ventured into manufacturing veneer and medium density fiberboards (MDF) using the oil palm trunks.

The oil palm tree produces the most abundant biomass, and oil palm fronds have been shown to be a very promising source of roughage for ruminants. Oil- palm fronds are available daily throughout the year when the palms are pruned during the harvesting of fresh fruit bunches. The fronds are also pruned during the pruning process to keep the optimum number of fronds on the palm tree. Currently, oil-palm fronds are left to rot between the rows of palm trees, mainly for soil conservation, erosion control and ultimately the long-term benefit of nutrient recycling. The large quantity of fronds produced by plantations each year and not utilized efficiently makes these a very promising source of roughage feed for ruminants. Feeding the ruminants with fresh chopped fronds is easier and requires less labor than cutting grass. Apart from that sourcing for suitable grass that could be used as feed for the ruminants becomes difficult as most plantations prefer to plant cover crops and spray grasses which are considered to be weeds. By using oil-palm fronds as a roughage source for livestock feeding, operational and management costs could be reduced as the farmer need not depend totally on manufactured pellets or fodder to feed his ruminants. Oil-palm fronds have been successfully used as a substitute for tropical grasses by ruminant producers in Malaysia.

The optimal levels of inclusion of the fronds in the total mixed rations on a dry matter basis were 50% for beef cattle, and 30% for dairy cattle and goats/sheep. The plantation could also venture into rearing of livestock as a process of live stock rearing in the plantations. The livestock could also bring down the cost field management and weed control by grazing on the weeds and ferns found in the plantations. Plantation owners who rear livestock in their plantations can save up to 40% of the cost of weed killers and this could result in overall cost reduction of field maintenance. In fact the bulk of the maintenance cost of the field is spent in the purchase of chemicals such as herbicides. In plantations where the mills are located, the oil
palm kernel cake could also be used as additional fodder for the live stock.

In all, every effort is made to put all parts of the oil palm tree to good use so that no part of it goes to waste or is just left to rot.  THE END.

References:

O. Abu Hassan, M. Ishida, I Mohd. Shukri and Ahmad Tajuddin (1994) Oil Palm Fronds as a Roughage

Feed Source for Ruminents in Malaysia, Livestock Research Division, Malaysian Agriculture

Research and Development Institute, Kuala Lumpur

P.D. Turner & R. A. Gillbanks (2003) Oil Palm Cultivation and Management2nd Edition, The

Incorporated Society of Planters, Kuala Lumpur.

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