Dairy wastewater and biochar – new report

Kathleen Draper, US CHARector at Ithaka Institute for Carbon Intelligence, has provided this link on the Biochar Farms & Gardens site to a study that should be of interest to the NZ dairy farming industry. This is further reinforcement of the role biochar could and should be playing in future nutrient management in NZ.

Biochar can be used to recapture essential nutrients from dairy wastewater and improve soil quality

Abstract
Recently, the potential for biochar use to recapture excess nutrients from dairy wastewater has been a focus of a growing number of studies. It is suggested that biochar produced from locally available waste biomass can be important in reducing release of excess nutrient elements from agricultural runoff, improving soil productivity, and long-term carbon (C) sequestration. Here we present a review of a new approach that is showing promise for the use of biochar for nutrient capture. Using batch sorption experiments, it has been shown that biochar can adsorb up to 20 to 43 % of ammonium and 19–65 % of the phosphate in flushed dairy manure in 24 h. These results suggest a potential of biochar for recovering essential nutrients from dairy wastewater and improving soil fertility if the enriched biochar is returned to soil. Based on the sorption capacity of 2.86 and 0.23 mg ammonium and phosphate, respectively, per gram of biochar and 10–50 % utilization of available excess biomass, in the state of California (US) alone, 11 440 to 57 200 t of ammonium-N and 920–4600 t of phosphate can be captured from dairy waste each year while at the same time disposing up to 8–40 million tons of waste biomass.

ABE has been posting frequently about dairy, nutrient management and water quality. Try clicking on the following tags to the left of this post: nutrient management; dairy farming; water quality; phosphorus; nitrogen. With this type of research continually being released, its hard to imagine that the biochar story can remain in the NZ media wilderness for much longer.


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