Digging into the details of Regenerative Farming

Can readers help Richard Sibly with research into the sustainability claims made about

methane emissions and soil as a carbon sink?

Regenerative farming is an approach that aims to enable the land, the soil, water,

nutrients and natural assets to regenerate themselves, rather than employ conventional

approaches that can deplete these natural resources.

Two excellent films featuring enthusiastic farmers advocate this approach are Six Inches

of Soil and Rachel’s Farm. The former is available to rent on Amazon Prime the latter is

available on the BBC iPlayer.

There are many good aspects in both these films, but there are a couple of points about

which I was less sure.

One is a claim that - contrary to conventional opinion - ruminants are not responsible for

the methane that exists in the upper atmosphere. In Rachel’s Farm, Rachel attends a

course in which the lecturer, Dr Walter Jehne, asserts that the methane emitted by

ruminants is neutralised in the vicinity of the animals by the hydroxyls, OH, given off by

the surrounding grasses.

Chemistry is not a specialisation of mine, but I have gleaned the following from some

research.

It is generally agreed that OH is a highly reactive gas that acts like an atmospheric

detergent, breaking down methane and other gases. The conventional view is that the

process occurs in the troposphere 6–19 km above the earth’s surface.

In contrast in Dr Jehne’s theory, the process occurs locally before the methane leaves

the vicinity of the cow because there is there an abundance of OH molecules created by

the breakdown by sunlight of water molecules emitted by local plants.

I have tried to find evidence for this theory but there is no scientific paper in the places I

rely on, Google Scholar and Web of Science. Dr Jehne is a scientist who retired from

Australia’s national science agency CSIRO in order to work on regenerative farming, so I

contacted CSIRO to ask them about the theory but have not received a reply.

The other point on which I am seeking input is the claim that when farmed

regeneratively, soil is a continuing carbon sink. I can see this working while the soil is

regenerated and soil carbon levels increase, but long-term, continuing absorption of

carbon would surely require soil levels to rise. Is this something that happens in

practice?

If WCAG newsletter readers can provide any help it would be greatly appreciated. Please

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