While everyone raves about organic food, organic growing practices don’t guarantee that the food we harvest will have higher nutrient density. Tests comparing certified organic and conventionally grown food aren’t always conclusive, except that organic foods tend to contain higher levels of beneficial phytochemicals. We’re also unlikely to compensate for these nutritional deficiencies by eating superfoods like kale, mushrooms, and avocados. Because, like virtually all of the food we buy, superfoods now contain fewer nutrients.
So what does the new research reveal? A simple method to grow nutritious food that anyone can use, whether beginners or experienced growers. That doesn’t require buying new-fangled equipment or costly fertilisers! All we need to do is provide our soil organisms with better resources. I’ll explain how in a moment. But first, let me explain why we now know this is the reliable way to grow nutrient-dense food.
As I’ve mentioned, while many assessments have compared the differences in the nutritional quality of organic and conventionally grown foods, until recently, few have directly considered the influence of the soil in which the food is grown.
Organic matter and microbial activity
By comparing nutrient density with different soil health measurements, the research shows that organic matter levels and microbial activity are the key indicators of the nutritional quality of our food.
While David Montgomery’s, Anne Biklé’s and other’s research provides only preliminary results supporting the role of organic matter and microbial activity, their findings about the importance of soil life are confirmed by research involving 20 different crops, 10,000 crop and 8,000 soil samples from Europe and the United States. According to Dan Ketteridge from the Bionutrient Institute, microbial activity was the only thing connected with nutrient variation. “Nothing else connected. Variety didn’t connect. The point of purchase didn’t connect. Certification labels or individual practices did not connect. What connected was if you had life in the soil.” “The more life, the more nutrients.”
Additionally, a farming trial carried out over 22 years by the Rodale Institute showed a positive association between organic matter, as gauged from soil organic carbon and soil nitrogen, with crop nutrient content and antioxidant levels. Unfortunately, they didn’t look at soil life.
These findings shouldn’t surprise us. The researchers used microbial activity to tell how much life was in the soil. Organic matter levels do the same because organic matter consists of soil microbes, other soil organisms, their remains and excretions, together with living plant roots and plant remains at various stages of decomposition.
Soil organisms have the skills
Why shouldn’t we be surprised? Because only soil organisms have all the skills to provide our crops and pasture grasses with a balanced diet! They have successfully managed the earth’s nutrient recycling facilities for billions of years. Our attempts at substituting for their efforts with fertilisers and minerals are amateur in comparison!
Imagine all the things that need to be done to enable plants to access the nutrients they require. Making the nutrients in dead leaves, roots, and other plant and animal waste materials available to plants is a complex process. It necessitates these organic materials being broken down into smaller parts by many different soil organisms. Microbes play a vital role. But earthworms, woodlice, snails, and a diversity of other soil organisms are also required. Together, they recycle nutrients, communicate with plants, and make the required nutrients available to plants for reuse. Their combined expertise is also needed to maintain a habitable soil environment.
Neglected food supply
So, what’s holding our soil communities back from applying their on-the-job training in our farms and gardens? In our blinkered quest to maximise plant growth to feed us and our livestock, we’ve neglected the food supply to our soil communities. We haven’t enabled our soil organisms to apply their skills to their best potential.
We won’t grow nutritious food relying on bio-fertilisers, compost, and mulch to add more organic materials and microbes to our soil. Depending on these inputs isn’t eco-logical. Our soil communities need their natural diet! A generous and diverse supply of leaves, manures, and other organic waste materials, combined with root tissues and exudates (the sugars and proteins plants secrete from their roots).
To reliably produce nutrient-dense food without reducing yields, we must change how we manage our vegetable gardens, orchards and fields. We’ve got to grow more vegetation and manage the above-ground plant biomass using techniques like grazing and cut-and-drop to supply more organic material to our soil. And for as much of the year as possible (recognising that many of us live in seasonally cold or dry climates).
In the research, many farmers producing nutrient-dense food increased the amount, diversity, and consistency of food supplies to their soil organisms by growing diverse cover crops between their cropping cycles. There are, however, many other eco-logical techniques that we can use. By responding to our local conditions and adapting how we grow our food, we can all benefit from the experts at managing our soil ecosystems and developing reliable ways to grow nutritious food.
Get practical advice to repair your soil ecosystem –
The author, Dr Wendy Seabrook is the founder and CEO of Learning from Nature. Learning from Nature supports food growers to grow food eco-logically.
