Vege grower Jim O'Gorman has spent the past 20 years studying the soil in his North Otago market garden.
Jim's research focuses on restoring land depleted by common agricultural practices.
The soil expert is keen to share his research findings with small-scale food producers around the world.
Jim first bought some land at Kakanui in the early 1990s.
The previous owners had been growing mainly cauliflower and broccoli, he says, and over many years applied synthetic fertilisers to boost productivity.
Early tests showed the soil was in bad shape and that discovery kick-started Jim's research into soil health.
"The thing I'm looking for is balance, to keep my soil in really good condition biologically and keep the chemistry right up to scratch."
Jim suggests farmers have biological tests completed on their soil.
"I call it 'tending to your underground cow' because if you're looking after the microbiology in your soil, you're looking after the broader aspects of it and you're training yourself to be better at soil management."
Jim's property is off the grid, there's only one water tap and only hand tools are used to work the land.
"Unless you can actually work in the way that they are living then you really aren't expressing what's actually capable of happening in the soil."
Jim sells the chemical-free produce he grows to local restaurants and cafes. None of it goes to waste.
"The chefs beat a path to my door. They know what they are looking for."
One chef has asked Jim to grow specific vegetables for him.
He has also supplied spuds to Government House for royal visits on a number of occasions.
"My potatoes are always sold in advance. I never have to go to the open market."
Jim featured in the 2009 BBC documentary
Jim's featured in various documentaries including The Dirt Doctor that screened on BBC Knowledge and Kathleen Gallagher’s Earth Whisperers Papatūānuku.
Last year he was invited to present a paper at the World Organic Conference in France. His presentation Fixing the Mess focused on the work he's done on his soil for more than 20 years, but Jim says unfortunately the conference was cancelled because of the Covid-19 pandemic.