Special report: Regenerative agriculture
The science-based
ORGANIC ADVOCATE Former climate change scientist turned organic vegetable grower, Dom Ferretti, says farmers can use pasture to remove carbon from the air. Anne Hardie reports.
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ou don’t expect an organic vegetable grower to say there’s nothing better for the soil than pasture and cows, but that’s exactly what Dom Ferretti advocates. As a former climate change scientist with a PhD who worked for NIWA on greenhouse gases (GHG) including carbon dioxide, methane and nitrous oxide, he’s qualified to make that statement. He says farmers can use pasture to remove carbon from the air and store it in the soil, reduce methane emissions from their animals and also reduce nitrogen leaching. After 12 years working on climate change issues, he now puts science into practice, using regenerative agriculture methods on an organic market garden in Nelson with his partner, Jeanette Ida. Ferretti Growers is a small business near Brightwater where they grow half a hectare of vegetables outside, plus 600m2 under plastic, with most packed into weekly boxes for their regular customers. For years they made copious amounts of compost for their soils and it cost them thousands of dollars each year, plus time to mix, load and spread it onto their gardens. Any imbalance in the compost caused an imbalance in the soil. It got them thinking about alternatives and when they learnt they could get enough nitrogen for their vegetables from cover crops, they decided to try that route. Dom says their first trial
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with cover crops was a “lightbulb moment” for him that showed they could grow their vegetables with a lot less work and spend just a couple of hundred dollars a year on a mix of seeds. Within the mix are plants with roots to open up the soil, add nitrogen and other nutrients, or produce flowers to attract beneficial insects. The positives don’t stop there. There’s less risk of nitrate leaching, the plants provide a stable form of nitrogen and improve the soil health, while providing the invisible benefit of sequestering carbon from the air and storing it in the soil. He says it’s not just about the nitrogen and carbon though. In the soil there’s the increased microbial activity and fungi networks that connect individual plants together and transfer not just nitrogen and carbon, but also water, other nutrients, minerals and trace elements.
GREAT POTENTIAL FOR PASTORAL FARMERS It works well for an organic market garden and Dom says the potential is even greater for pastoral farmers who can make a difference in the battle against climate change. He says regenerative agriculture has the ability of increasing the soil carbon by 1% per hectare per year by sequestering
Climate change scientist turned organic vegetable grower, Dom Ferretti, in his organic garden.
Dairy Exporter | www.nzfarmlife.co.nz | June 2021
