A study conducted by two Swiss-based research institutes is showing that turning abandoned pasture into an oil palm plantation can be carbon neutral, providing support for producing palm oil on degraded and neglected lands as a sustainable alternative to deforestation for the production of the commodity.
The new study by the Swiss Federal Institute of Technology Lausanne (EPFL) and the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), showed that the carbon footprint of palm oil production in abandoned land, in this case, former pastures in Columbia, remained unchanged compared to when the land conversion took place, EPFL News said on its website Thursday (21/11).
“Our study is the first to look at the carbon footprint of palm oil production over the long term – that is, across two plantation cycles, since oil palm trees are replaced every 25–30 years,” says Juan Carlos Quezada, a Ph.D student at EPFL’s Ecological Systems Laboratory (ECOS) and the study’s lead author. “It’s also the first to explore how converting pastures into oil palm farms affects soil quality and fertility over the long term, looking at all soil layers, not just the surface.”
Conducted as part of the Oil Palm Adaptive Landscapes (OPAL) project and involving project partners from Switzerland, Indonesia, Columbia and Cameroon, the study looked into soils in oil palm cultivation for years, in an effort to develop more sustainable methods for growing this crop, which has been blamed for leading to the massive deforestation taking place in palm oil-producing countries in the past decades. It was conducted in a 56-year-old oil palm plantation in the Los Llanos region of Columbia, the world’s fourth-largest palm oil producer, that were formerly pasture areas.
Palm oil production has been criticized by environmentalists because of its large carbon footprint and negative impact on biodiversity. A 2018 study carried out by EPFL and WSL had shown that planting oil palm trees in deforested areas does not make up for the lost carbon storage capacity.
The new study, its findings were published in Science Advances, a peer-reviewed multidisciplinary open-access scientific journal on Wednesday (20/11) calculated the crops’ carbon footprint since the conversion of the pasture land into oil palm plantations and it found that the total carbon storage – taking into account both vegetation and soil stocks – was unchanged relative to when the land had been used for pastures.
“The problem lies with the negative carbon impact and loss of biodiversity caused by deforestation. But the main palm oil-producing countries have largely abandoned pastures that could be converted favorably, thus limiting the massive carbon loss resulting from deforestation.” Alexander Butler, a co-author of the study, was quoted in the EPFL news article.
In tropical climates, pastures – especially those that have been neglected and degraded – commonly consist of large grassy areas with a few small trees scattered around. Planting dense populations of oil palm trees – which can reach 15 meters in height – on these pastures can increase the carbon capture rate per unit of surface area, because of the palm trees’ roots, trunks, and leaves, as well as the vegetation around them, the article said.
As the roots and other parts of the old trees decompose, they nourish the soil and partially offset the carbon initially lost in the upper soil layer when the pastureland was converted. As a result, over the long-term cultivation period, the amount of carbon stored in the ecosystem remains unchanged compared to the initial level before the land conversion took place.
Indonesia and Malaysia, the world’s two top palm oil producers which together account for more than 85 percent of the world’s palm oil supply, do not have much large pasture areas but have expanses of degraded land which had long been logged out and left neglected.
“We should bear in mind that palm oil in and of itself is not harmful – neither to our health, when eaten in moderation nor to the economy. And we’re not talking just about multinationals – the incomes of hundreds of small farmers in Colombia and other countries depend on it,” Buttler, who also heads ECOS, was quoted in the EPFL report on the study.