Scientists Stumble Upon Way to Reduce Cow Dung Methane Emissions

Twice a day at milking parlors all over New Zealand, the world’s biggest dairy exporter, sheds are hosed down to wash away cow dung into large manmade ponds.

In an attempt to recycle the water in the lagoons, two local scientists — Keith Cameron and Hong Di — began testing the addition of polyferric sulfate, a chemical that’s been widely used in wastewater treatment to separate liquids from solids. The process worked, but that didn’t prove to be their most interesting finding.

When the pair of soil and physical sciences professors at Lincoln University ran checks to monitor for any impact on ...