Watching the studies come out about the merits or demerits of organics is a little like watching World Cup soccer. A large study done at Stanford in 2012 claimed organic food to be no more nutritious than chemically grown. Score one for that side. But a report newly published in the British Journal of Nutrition finds organically raised vegetables to have more antioxidants, less cadmium (a toxic metal in commercial fertilizer) and fewer pesticide residues. Score one for Team O.
Now what? Nobody’s exactly rooting for chemical residues, or for cadmium. Antioxidants are superstars — if they’re in a tomato or head of broccoli, not in a pill — but they don’t seem to be fully understood. Important to study, yes, but only as part of a vast web of interactions in which one part touches many others.
To me, the groundbreaking scientific revelations in recent years have been about how little we all know. The natural world does not bow before the mighty human brain. More accurately, our brain bows before the miraculous, newly discovered empire of good bacteria in our gut. Yet we must feed that gut every day and make dietary decisions based on simple observation and common sense.
As a gardener, it’s been my experience that soil containing a full range of macro- and micro-nutrients, in proper balance, produces strong plants that tend to ward off pests and diseases. I create that soil by enriching it with a composite (known as compost) of varied organic materials broken down by bacteria and other organisms in the soil. This is a natural partnership between biology and chemistry in which nutrients are made more available to plants.
Both flavor and nutrients are at stake. A paper presented by Charles Benbrook at the American Society for Horticultural Science Colloquium in 2007, summarizing studies on nutrient density in organic vs. conventional produce, notes: “The nutrient and antioxidant dilution often observed in high-yield, [high-nitrogen] systems . . . tends to reduce the richness and intensity of flavors.”
And a panel of scientists presenting at the 2009 annual meeting of the American Association for the Advancement of Science concluded: “In hundreds of studies, scientists have shown that incrementally higher levels of fertilizer negatively impact the density of certain nutrients in harvested foodstuffs, hence the name, the “dilution [of nutrients] effect.”
How fruiting crops are ripened can affect flavor, too. Time and sun do a better job than ethylene gas. With leafy crops, those picked and eaten fresh seem more alive, and more life-giving.
I know a lot of farmers, especially small-scale ones, who use organic methods and sell mostly to local markets. The better they are at the game, the less they rely even on plant-based pesticides approved for organic use.
The more they use succession cropping, season extension and some of the newer tools being developed for small farms, the better their yields, which acre for acre often put conventional farming to shame.
These farmers study the natural world like a book and learn what works. They are not saints, but they tend to be humanists in the loose sense of considering humanity as a whole, which means protecting the natural resources of soil, water and air. Go look at one of their farms and then go look at a big commodities farm. Which one has bees in the air and earthworms in the soil? Whose food would you rather eat?
“Organic is too expensive,” you so often hear. But no, conventional food is too cheap, propped up by government subsidies and by shortcuts such as herbicides and toxic sprays that cost us all in the long run. Subsidize low-income food-shoppers instead so that they can make an enlightened choice about what to feed themselves and their kids. Is any decision more important than that? Give food systems a level playing field. Then let’s see who wins.
Tip of the week:
Use hand pruners — mind your fingers — to remove blighted tomato leaves to improve air circulation and curtail the spread of disease. Bag the leaves and clean up any fallen debris. Make a note of badly infected varieties and pick blight-resistant varieties next year. Feed groomed plants with a fertilizer formulated for tomatoes, or apply a liquid fish or kelp emulsion feed. — Adrian Higgins
Damrosch’s latest book is “The Four Season Farm Gardener’s Cookbook.”