Digging the dirt
Growing great crops is all about starting from the ground up, giving your soil the love that it deserves, writes Nadia Lim.
Being a regenerative farmer means starting at ground level. Everything we do is focused on regenerating the land, particularly the soil. It always comes back to the soil, whatever you’re growing.
Before MasterChef, my professional background was in nutrition and dietetics. When I started studying soil, I discovered there are a lot of parallels between soil health and human health.
Studying soil might sound a bit dull, but I’m a bit of a science geek and, to me, it is exciting. I had a lightbulb moment where I realised that the human body is like the soil, in that the microbiology in a person’s gut and the microbiology in the soil are so essential. It’s responsible for how each performs.
With the human body, you want to build strength, health and resilience from the inside by eating nutrient-dense food to give it vitality and immunity. The idea is that you build maximum potential by eating well, just getting a little help from medicine when necessary, rather than relying on it.
That’s pretty much the same with any good farming practice. You need to work on the soil and the land’s health from the inside out, by building diverse and healthy microbiology within the soil.
You have to make sure it has all the minerals it needs, and that its ecological system is working perfectly. Sometimes a little intervention might be needed in terms of fertiliser, but you shouldn’t have to rely on it.
Unfortunately that’s where I think a lot of conventional farming, both agriculture and horticulture, is today. I was quite surprised when I learnt about all the schedules that people tell you to stick to in farming, that you should put on this much fertiliser at this time of year, or spray that crop at that time of year. Everything might be perfectly on schedule when you follow those ‘‘rules’’, but nothing in nature works like that.
Every year, every season is different, and every piece of land is different. You really have to know your land well and work with what is unique to it, whether you’re a farmer or someone with a little backyard garden.
Looking after your soil is just like looking after your body. It needs to be cared for to ensure it’s alive. Healthy soil is teeming with microorganisms – bacteria, fungi, protozoa, nematodes – they all operate in beneficial symbiotic relationships with plants.
In simple terms, a plant gets energy from the sun that it converts to carbohydrates (through
photosynthesis). It then delivers this energy source, through its roots, to these infinite numbers of incredibly clever microbes that all have thousands of functions.
These micro-organisms help plants grow by increasing the availability of nutrients. It’s simple when you think about it: things grow better if the soil is alive. To feed your soil, have living roots in the ground. Microbes live off them, so more roots equals more microbes. Roots also retain moisture in the soil, which keep it more resilient against drought.
Conventional farmers till and plough their land to get rid of crops after harvest and aerate the soil, but we’re a no-till, no-plough farm. Instead, we harvest our crops and then use the stubble as a mulch to help retain moisture in the soil.
The downside is that it takes time, because you have to wait for it to rot naturally. But there are so many benefits when the nutrients are returned to the soil. I use these principles in my home garden, too. I weed only when necessary, such as if the weeds are competing with my plants. I’m not against clover in my vegetable garden because it’s a nitrogen fixer.
Biodiversity is another important contributor to soil health. Instead of following the programme of planting the same crop in the same paddocks every year, we rotate plantings to encourage nutrients to return to the soil and prevent the risk of nutrient depletion, soil-borne pests and diseases. Home vegetable gardeners will know how this works. After you’ve grown a heavy-feeder such as tomatoes, you need to plant a soil-feeding crop such as beans or peas.
I don’t use synthetic fertilisers in my home garden, and my husband Carlos will only use a small amount of fertiliser on the farm, on a few paddocks that need it.
It’s a bit like a human body. You can’t really over-eat nutrient-dense food, but you can overdose on vitamins if you’re taking supplements. That’s the same with soil. If you’re using natural boosters such as compost, worm castings, seaweed, and fish hydrolysate, you are much less likely to throw things out of balance.
Soil health is intricately linked to human health. Healthier soil means healthier plants, which means more nutrient density, so the humans who eat it consume more of those vitamins and minerals.
New Zealand is lucky in many ways. The soil has only been cultivated for 150 years or so. In countries such as the United States, the soil has been depleted over hundreds of years. That’s why we need to be careful.
‘‘Looking after your soil is just like looking after your body. It needs to be cared for to ensure it’s alive.’’