PETALING JAYA: The slash and burn method of land clearing is 40 times cheaper than using machines, thus making it difficult for Indonesia to stop open burning.

“The underlying factor is cost,” said Dr Helena Varkkey of the Department of International and Strategic Studies, Universiti Malaya.

Dr Varkkey, whose expertise is in environmental politics, said that based on research done by others, the cost per hectare in using the slash and burn method is approximately USD5 per hectare.

Using machines would cost about USD200.

She pointed out that small-scale farmers were not the primary source of fires and the culprits were the 60% to 80% of commercial plantations.

“The problem is that most commercial plantations also prefer to use fire, for similar cost-related reasons.

"These companies are able to avert the risk of being caught and punished for open burning,” said Dr Varkkey who was written papers on the haze and oil palm.

She explained that the companies would hire subcontractors to clear land and if they were caught for burning, they claimed to have instructed the subcontractors not to use the slash and burn way.

These companies, she added, often cultivate healthy relationships with local and central government officials.

Another situation that led to the fires causing transboundary haze that has affected Malaysia and Singapore in recent days is the increasing use of peat soil to grow oil palm trees.

Dr Varkkey said there are regulations that forbid the use of peat land for commercial purposes

“When drained for use, peat dries quickly and becomes highly flammable.

"Even if these companies do not deliberately burn for land clearing, drained peat is highly susceptible to accidental fires.

"These companies are already placing their concessions at risk of fires by opening up these areas,” she said.

She added that while pulp and paper or rubber plantations owners also used fire to clear land, the effects were not as severe as the burning of peat soil.

“When peat burns, it releases carbon-rich, sooty smoke that result in very bad haze, and the fires are very hard to put out.

"Fires on other types of land do not produce such choking smoke, and are usually easier to put out,” she said.