Sowing the seeds...
Sunflowers are not just beautiful to look at but are a shining example of a crop that gives back in many ways, writes Nadia Lim.
In late summer and into early autumn, there is nothing more beautiful than seeing fields of sunflowers with faces glowing. They’re the best selfie buddies, and if we had a dollar for every person who has stopped to take a photo with them, we’d probably have made 10 times more than what we will make out of the crop itself.
We planted almost one million sunflowers – 968,000 to be precise –on about six hectares of land. We didn’t just grow them for their good looks, or even their oil and seeds, though those are great by-products. The reason we were drawn to planting them was for their deep taproots, because sunflowers are as useful below the ground as they are beautiful above it.
Sunflower roots are deep and thick, which are needed to keep those heavy heads of flowers upright. This is important for many reasons. Before we moved to the farm, these paddocks had been used to grow barley over and over again, so the soil had become quite heavy and compacted, and a bit depleted.
Growing sunflowers on it instead has helped to naturally aerate the soil, thanks to those strong roots that dig down deep, penetrating and breaking up heavy clumps of soil along the way. As a result, it also encourages rainwater to infiltrate more deeply.
On top of that, the best way to kill weeds is with shade; so an allelopathic plant that grows tall and provides shade will suppress weeds.
The plants draw carbon from the atmosphere (in the form of carbon dioxide) and convert it (via photosynthesis) into carbohydrates and sugars, which are released (via its roots) to all the wonderful microbes in the soil, in exchange for other nutrients it needs. This symbiotic relationship benefits everyone – the sunflowers, the soil microbes – and the more microbiology we have in the soil, the more it benefits us.
Everything starts with the soil, and the more your soil is alive and teaming with microbes, with life, the better.
We were told we were the last growers in New Zealand to harvest their sunflowers. My husband Carlos harvested the seeds this month. We planted them late to avoid the possibility of frost damage (at 650-700 metres above sea level, we’d be the highest altitude sunflower farmers in New Zealand, for sure).
However, we also don’t chemically spray our crops, so we have to wait for them to dry out and die off naturally. And it’s a long waiting game.
During that time you’re vulnerable to the birds feasting on the seeds. I must say a special thanks to “our” hawk, whom I’ve named Harvey, for sitting on the fence post for days on end doing his best to scare off the birds (I like to believe he was guarding our sunflowers this whole time).
The seeds are harvested with a combine harvester, which drives through the paddock of dead, brown sunflowers, cutting off the heads that are filled with seeds, and then thrashes them to separate out the seeds. The seeds are then delivered to The Good Oil, a locally owned company that produces only New Zealandgrown canola and sunflower oil, to extract the oil.
Sunflower seeds are naturally oily, so not much has to be done to them, simply crushing and pressing them with a huge drill to push out all the oil, which is then poured through a filter and into bottles. No refining, heat or chemical treatment is needed, and because it’s a locally grown and produced product, no food miles are attached to it. I love that we’re keeping it local, simple and natural.
The variety we planted is a high oleic variety of sunflower, so the oil has a high level of monounsaturated fats. Sunflower oil also has a relatively high smoke point, so it’s great for cooking with. I do prefer to use it in savoury dishes though, rather than sweet. I did try putting it in a cake but the flavour was a bit strong, which is often the case with cold-pressed, non-refined oils. It’s brilliant for stir-fries, pan-frying, and roasting.
That paddock, once a glorious sea of golden faces, is now an ugly field of dead, brown stalks and heads on the ground. While this sight isn’t as Instagrammable, everything is useful. The stalks will be chopped and dropped and left to rot to return all the carbon back to the soil. Because of their bulkiness, carbon sequestration is higher in sunflowers than many other plants. This will also feed the microbes again, as well as act as a mulch, keeping in the moisture and suppressing weeds.
So thanks to those sunflowers (and Carlos, the sunflower farmer), the soil in that paddock will be richer with microbiology, moisture and, soon, carbon. It will also be well aerated and ready for the next crop.
A “nitrogen fixer” (phacelia, peas or clover) will go in next to add some natural nitrogen back into the ground. Nitrogen fixation is essential for plant growth. It’s important in home gardens, too. After you’ve planted heavy feeders such as tomatoes or brassicas, follow them with a nitrogen-fixing crop, such as peas or beans, or a green manure cover crop.
We’ll plant a second nitrogen-fixing crop next season, then go back to wheat or barley. As you can imagine, this kind of crop rotation and diversity is far better for the soil than mono-cropping (planting the same thing in the same place season after season).
Next year, we’ll plant another one of our paddocks in sunflowers, and put it through the same cycle.
I’m already missing the sunflowers and can’t wait to see their sunny faces again.