Clarification Sludge
The effluent from the clarification station, which accounts for 75% of the total BOD generated in the mill, is processed via a decanter and the resultant cake is mixed with inorganic fertilisers and dried in a rotary drier to produce organic fertilisers commercially marketed as Supergro, Turfgro and Bajaria. Apart from adding value to waste, the system reduces methane production by 75%. Additionally, the rotary drier used for drying the fertilisers also functions as a scrubber of unburnt carbon particles in the flue gas producing, in the process, cleaner emissions.

Steriliser Condensate
The steriliser condensate is anaerobically treated in biodegradation ponds and the digested effluent used for irrigating oil palms. Apart from improving the soils physical, chemical and biological properties, land application of digested effluent increases oil palm yield by up to 25%. Presently about 140 hectares in the Company is under land application.

Organic Matter recycling on Land
Organic matter is an important constituent of soil health. It needs to be maintained at a healthy level for sustainable crop production.
Malaysian soils, like most tropical soils, are low in organic matter. The situation in some areas is further aggravated by the fact that oil palm is already in the second or third generation of planting where organic matter depletion can be a serious problem.
Besides improving oil palm growth and yield, the recycling of the pruned fronds, trunks at replanting, spent male flowers and empty fruit bunches on land, on mineralisation, release large quantities of locked carbon and plant nutrients to the soil. The total organic matter recycled on land in United Plantations Berhad in year 2001 amounted to 350,000 tonnes, equivalent to 140,000 tonnes of carbon. The fertiliser value of the recycled biomass was calculated at RM 12 million.
Herein, it is gratifying to note that the maintenance of the carbon cycle by returning the biomass to the field has enabled scout harvesting to commence at 28 months after planting rather than 36 months.

Integrated Pest Management

Herbicides
Blanket weeding is discouraged. Spraying is confined to the circle or strips along the harvesting paths, which represent only about 25% of the area.
Leguminous cover crop establishment during the early years reduces the need for spraying.
The tropical climate with a high year-round soil microbial activity rapidly degrades the pesticide residues rendering them harmless to the environment.

Insecticides
Integrated pest management (IPM) is increasingly practised in the plantations. This consists of regular pest monitoring, conservation of natural enemies through establishment of broadleaf flowering weeds and the judicious use of chemicals.
Greater emphasis is given to the use of safer and more target specific insecticides with fast-fading residues that are soft to the environment e.g. Pyrethroids, Bt. Formulations.
With regular monitoring and detection, outbreaks are nipped in the bud, requiring limited spraying.

Greater emphasis is laid on operator safety through the provision of suitable protective clothing as well as training in the safe use of pesticide.

Water Management/Rain Harvesting
The consumptive use of water (evapotranspiration) of oil palm is around 150 mm per month. To meet this requirement, the monthly rainfall should equal or preferably exceed this figure failing which moisture stress will occur. The rainfall in the Company’s estates ranges from 1600 to 2500 mm per year, with the average being 2000 mm. Monthly distribution is reasonably uniform, but in some estates, dry periods of one to two months may occur where the monthly rainfall is less than 100 mm. To conserve moisture during this period, a series of weirs have been constructed across the collection drains to harvest the rainfall and hold back water to raise the water table to within 60-90 cm from the surface. On average, one weir is provided for every 40 to 60 hectares. Assisted by the watergates at the discharge ends of the main drains, the weirs have been very effective in minimising the adverse effects of water stress especially on the fragile acid sulphate and peat soils.

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Oil palm biomass recycled on land and its contribution to the carbon economy of the soil (during the course of one generation of palms) - PDF 23 KB

Estimated fertiliser value of oil palm biomass residues recycled on land in United Plantations Berhad in 2001 - PDF 30 KB

Level of utilisation of palm biomass residues and waste in United Plantations Berhad in year 2001 (dry matter basis) - PDF 40 KB