Craigmore Sustainables is trialing EcoPond, a technology that reduces methane from effluent ponds developed by Ravensdown in collaboration with Lincoln University.

EcoPond became part of the newly established Ravensdown entity, Agnition, earlier this year.

In February, Craigmore implemented the technology on its 400-hectare dairy farm in Glen Eyre, Oxford.

Glen Eyre is one of 54 properties managed by Craigmore.

The New Zealand-owned company manages over 25,000 hectares of dairy, grazing, forestry and horticultural properties, managing over $1 billion in assets and employing over 250 staff.

"Ecopond could play a key role in supporting farmers to reduce methane and help New Zealand meet its climate change targets," Craigmore general manager of farming Stuart Taylor says.

With nearly all dairy farms using effluent ponds, the second largest source of on-farm emissions, the technology is set to be a game changer.

EcoPond could enable farmers to continue to reduce their farm's environmental impact.

According to a study by AgResearch in 2020, New Zealand has the lowest carbon footprint for on-farm milk production globally.

New Zealand dairy farmers already produce 20% fewer emissions per kilogram of milk solids than in 2020.

"EcoPond is an important trial for us because we are keen to apply innovative ways to the reduction of emissions and minimise environmental impacts,” Taylor said.

"This technology is just another example of New Zealand's primary sector leading the world in reducing emissions and playing our part in reducing climate change.”

The EcoPond system uses iron sulphate, an additive normally used in drinking water, to reduce methane emissions by up to 99%.

Iron sulphate restricts the growth of methane-producing microorganisms known as methanogens.

EcoPond is an inline mixing system that intercepts effluent from the dairy shed, feeding it through a stone trap and separating out solids.

Run-off is intercepted and passed through a mixing coil, where effluent is dosed with iron sulphate.

Sensors in the pond feed information back to a Programmable Logic Controller (PLC), which automatically controls the system, ensuring the correct dosage of the additive according to the pond size or effluent volume.

"It's a fully automated plug-and-play unit," Ravensdown EcoPond product manager Carl Ahlfeld said.

"It's very easily installed into existing effluent systems."

Results at the Craigmore farm have been promising, with tests undertaken in May at Glen Eyre showing a 95% reduction in methane in effluent after being treated with iron sulphate through EcoPond.

Ahlfeld said initial test results have also shown added benefits of a significant reduction in E-coli and hydrogen sulphate gases, reducing odour.

"It's great to see Craigmore take a leadership role and demonstrate what can be achieved with EcoPond technology," Agnition chief executive Jasper van Halder said.

"Partnerships and innovation are required in the sector.

"It's hard to beat practical on-farm use to really demonstrate the EcoPond advantage, and partners like Craigmore show us the future of farming."

by Claire Inkson