New Zealand brings in around two million tonnes of palm kernel expeller every year, mostly as feed for dairy cows.
But University of Canterbury researchers say the effects of PKE on the sustainability of our agricultural systems call for an urgent assessment.
The researchers have tested samples of palm kernel expeller and found higher levels of magnesium, phosphorus, and iron than is recommended for cows.
They say it is a complex topic, because the expeller may be a good alternative fertiliser.
However, they note that NZ also produces its own biowastes.
If future research finds that our own local biowaste provides similar beneficial nutrients as palm kernel expeller, then this could contribute to a circular economy where waste products are used rather than dumped.
The researchers also say palm oil has been linked to the deforestation of virgin tropical forests, and the excess elements discovered in their study warrant an urgent re-assessment.
The work is derived from the Centre for Integrated Biowaste Research funded by Strategic Science Investment Funding from Ministry of Business, Innovation and Employment, New Zealand (contract C03X1701).
A media release says:
“New Zealand imports approximately 2 million tonnes of palm kernel expeller (PKE), a waste product of palm oil processing, from Indonesia per year to support our dairy farms. At current prices, this costs approximately $800,000,000 per year.
“The chemicals contained in the PKE can significantly affect our soils and animals, both positively and negatively.
“PKE may alleviate some micronutrient deficiencies in livestock and provide contaminant-free phosphorus into our soils.
“However, some chemical elements may cause nutrient imbalances in animals, as several elements exceed maximum tolerable levels for animal feed.”
The media release concludes:
“An assessment of the effects of PKE on the sustainability of our agricultural systems is urgently needed.”
Link to research (DOI): 10.3390/su142315752