2 Jun 2012

Scientists investigate carbon in dairy farm soils

6:41 am on 2 June 2012

Waikato University scientists want to find out why carbon content in dairy farming soils has declined and how that might be reversed.

As a starting point they have set up equipment on a Waharoa dairy farm that measures the amount of carbon dioxide going in and out of the soil up to 20 times per second.

Research team leader Louis Schipper says carbon is an essential ingredient in soil, so it's important to know what's happening with it.

Professor Schipper says the project goes beyond measuring the carbon dioxide exchange in and out of soil.

''We've got to couple that to recognising other exports and imports of carbon from the dairy system to (obtain) a true carbon balance for a dairy farm,'' he said.

Professor Schipper says they will also investigate whether farmers could build up carbon levels in soil by changing the pasture mix.

He says carbon in organic matter is essential for maintaining the quality of soils, by providing good soil structure, and retaining moisture and nutrients.

But Professor Schipper says the carbon content in dairy farming soils has been declining.

So later in the project the researchers will investigate whether varying the pasture from the standard ryegrass-clover mix, could increase carbon levels again.

Professor Schipper says they want to include things like chicory or plantain in with ryegrass-clover.

"We're hoping that we can show that an increased sward mixture would be able to capture more carbon out of the atmosphere, convert it into root material that then has flow on effects to the storage of carbon lower in the soil".

The research is being carried out through the Agricultural Greenhouse Gas Research Centre.