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University of Alberta research finds potential for converting pulp mill waste into fertilizer

A new University of Alberta research finds that pulp mill waste could be converted into organic fertilizer instead of being sent to the landfill.

The two-year study conducted on a hybrid poplar tree plantation in northern Alberta reportedly showed that adding biosolids – wood and other fibres left over from pulp and paper production – to conventional fertilizers decreased harmful greenhouse gas emissions from the soil.

A University of Alberta press statement explained that conventional fertilizer, containing industrially produced urea, has been shown to stimulate nitrous oxide, a major contributor to global warming. Though pulp mill biosolids are generally rich in organic content and low in toxicity, it wasn’t known how they might also have an effect, says Scott Chang, the study’s lead author and a professor in the Faculty of Agricultural, Life & Environmental Sciences.

Combining biosolids and conventional fertilizer also improved soil fertility, the study showed.

The findings reportedly provide new insight into what effect biosolids could have if they were redirected for use on tree plantations that feed the forest industry.

The results of the study show the potential for developing a “win-win strategy” in managing pulp mill waste, Chang notes.

“Repurposing biosolids as an organic fertilizer, which may help reduce greenhouse gas emissions, could improve the sustainability of the pulp and paper industry,” he adds.