Wetenschap - 21 maart 2019

Earning money by storing carbon

Roelof Kleis

By changing how they till the soil or growing different crops, farmers can capture and store more carbon in the soil. And they can earn money by doing so.

Text and photo Roelof Kleis illustration Annet Scholte

Series: Experimenting for the climate

The Netherlands aims to cut its greenhouse gas emissions by 49 per cent by 2030, compared with 1990. How we are going to do that is to be laid down in a comprehensive Climate Agreement. Ahead of that, ministry of Agriculture funds are being used for numerous experiments in emission reduction. WUR is coordinating these pilot projects for the Agriculture and Land Use sector. Resource is currently taking a look at these experiments in four numbers. This week, episode 3: the soil.

‘This agenda will change agriculture’. Peter Kuikman, project leader of the Soil climate pilots, speaks with great conviction. He has just explained how Dutch farmers are now in possession of a new business model: carbon capture in organic matter in agricultural soils.

There is nothing scary or unnatural about this, emphasizes Kuikman. ‘We are talking about CO2 that has been converted into organic matter via plants. So it’s in plant waste matter: leaves, roots, stems, in some cases partially converted by fungi, bacteria and other soil life. A question of soil formation and recovery. We are trying to speed up that process by putting more carbon in the soil and making sure less carbon escapes from the soil.’ And then he brings in his favourite metaphor. ‘See the soil as a piggy bank. You can’t save in a piggy bank with a hole in it. It’s hard to save if you spend more than you earn.’

Less ploughing

There are many ways of storing carbon in the soil. Livestock farmers can use different grass varieties with deeper roots, thus storing carbon in deeper layers of the soil. They can also grow maize with strips of grass in between, so that no agricultural land is exposed and you protect the organic matter. Arable farmers can keep carbon in the soil by tilling the soil less: turning it over causes loss of carbon. Or they can rotate crops, grow winter grains and buy organic manure from elsewhere, which would otherwise be incinerated.

Throughout the country, about 120 farmers are taking part in pilot projects in which they are trying to capture more carbon in the soil in this way. So far, they are doing this on a voluntary basis, but that is set to change. It is possible to earn money from carbon storage, says Kuikman. In fact, that is the idea the project is based on. ‘A farmer is not going to do all this if it doesn’t pay off. The farmer wants a fair price for his efforts, through a system of carbon credits that we are developing.’

Arable farmer Jaap Lodders: ‘We see the soil as a battery. We are not out to exhaust it.’
Arable farmer Jaap Lodders: ‘We see the soil as a battery. We are not out to exhaust it.’

Soil as sponge

Arable farmer Jaap Lodders from Swifterbant is one of the farmers participating in the project. A rather atypical one, as he has been storing carbon on his 125-hectare farm for more than 10 years. Lodders is a member of the Skylark Foundation, a farmers’ club that aims at sustainable practices. He generates all his own electricity; the roof of one of the barns on his farm is covered in solar panels. He holds sustainability certifications such as Planet Proof and Global gap. And now he is saving carbon, partly by ploughing less deeply and shredding his wheat straw and leaving it on the land. ‘Some more of that straw goes to a neighbouring duck farm, and I get it back as manure.’

Circular agriculture of the kind Agriculture minister Carola Schouten has in mind is what Lodders has been doing for a long time. The farmer’s main motive is not so much to give the climate a helping hand. ‘I started doing it in order to do something about soil compaction,’ explains Lodders. ‘On compacted soil, you get big puddles after heavy rain. By putting more organic matter into the soil, it can absorb and retain more water. You can see it as a kind a sponge.’ Emissions reduction is a secondary benefit for Lodders. ‘Improving the soil and cutting emissions go together. We arable farmers depend on the soil. We want resilient soils and that’s something you have to invest in. That’s how we see the soil, as a kind of battery. We are not out to exhaust it.’

 Taking care of the soil like this is Lodders’ business model. He is not yet convinced that carbon storage could be an earner in any other sense. ‘We tried that within Skylark too, but it never really got off the ground.’ Nevertheless, he willingly takes part in the pilot. In his case, that actually means not working a strip of land as he usually would. ‘To create a baseline measurement.’

The soil is a piggy bank; you can’t save in a piggy bank with a hole in it

Carbon balance

That baseline measurement is important. It is only useful to remunerate farmers for carbon storage if the savings are measureable and can be reported. For that reporting (at the European level), Kuikman explains that a nationwide network of more than 1400 measuring stations has been formed. The 120 participating farms are part of this. The idea is to repeat the measurements every five years, to monitor carbon levels in the soil. Kuikman: ‘We also want farmers to document the carbon balance on an annual basis. Which crops are grown, how and how often the soil is tilled, how much fertilization takes place, etc. If the overall balance is positive, you get a payment for it.’

Kuikman firmly believes in the new business model. ‘There will be a new way of farming and of thinking about business operations. There will be more emphasis on long-term carbon storage. That is the challenge for the farmers.’