I think most people who are environmentally conscious, peak oil aware, or otherwise green-leaning (or should I say “brown-leaning“?) will agree than monoculture is bad. Growing a hundred (or even a thousand) contiguous acres of a single crop is asking for trouble. Doubly so if that crop is vegetatively propagated, since the individual plants are genetically identical, and so, identically susceptible to any pest or disease that happens to infiltrate the defenses. (See: Irish Potato Famine.)

To get around such susceptibility, many have taken up the flag of permaculture. Others follow in the footsteps of Joel Salatin, or Gene Logsdon, or Elliot Coleman, or Scott and Helen Nearing. If you read these authors, they aren’t always in agreement, and you may start to wonder who to listen to. Which method is best? Which author is right? What is the answer to the ultimate question of sustainable food production?

After reading Return to Resistance by Raoul A. Robinson (available for download here), I think I’ve discovered the answer.

It’s not that this book contains the answer, though maybe there’s a case for that. The conclusion I came to is that the monoculture problem applies to how we grow things as much as what we grow. We must have diverse approaches to sustainability. A single solution, whether it’s the Nearing’s low-on-the-food-chain vegetarianism or Salatin’s plant and animal symbioses; whether it’s permaculture’s emphasis on trees and perennials or Elliot Coleman’s emphasis on annual vegetables; perhaps even whether it’s organic vs. chemical farming — a single universal approach is inherently vulnerable.

The vulnerabilities Robinson brings to mind are pests and diseases. Modern large scale farming, to use an extreme example, essentially has to use tons of chemical fungicides and pesticides and antibiotics, because the plants and animals have lost all of their natural resistances. The more they are protected by chemical and pharmaceutical defenses, the more their natural defenses fade away.

Breeders can sometimes manage to arrange for a short-term biological resistance to pathogens through something Robinson refers to as vertical resistance. In essence, they find a particular genetic lock that bars entry to a particular pest completely. It’s invariably hailed as a breakthrough, a triumph of science, the beginning of the end of disease and pestilence. It also tends to be both expensive and short-lived.

In essence, the monoculture of a modern farm has put the same lock on every door. Once the lock is picked — and history tells us that it will be picked  — the pathogen has free access to every single specimen. Hence, the chemical arms race on the food supply front lines.

The problem is not confined to large scale commercial farming though. Even open-pollinated vegetables can have some vulnerabilities, if the genetic base is too narrow, if it has lost some ancestral resistances, or if it is offered too much external protection from pathogens. Unfortunately, if natural resistance is not tested, it is essentially bred out of the line.

In a natural system, it’s not in the parasite’s best interest to devastate its host, since that would threaten its own survival. As a result, a natural system might have ten different locks, or a hundred, so that although the pest may pick a lock and damage or destroy a tenth or a hundredth of the hosts, it won’t do widespread damage to the population as a whole.

Natural systems rely on horizontal resistance. Once an infection or infestation has begun, the target organism can use a variety of means to minimize the damage. The genetic diversity of a population ensures that there is always a spectrum of susceptibility, with some specimens struggling or succumbing, while others thrive in the resulting void.

According to Robinson, the most effective way to take advantage of these natural defenses is to allow and encourage this horizontal resistance instead of vertical resistance. The latter can be painstaking to achieve, and results are often quite temporary. And vertical resistance is nearly impossible in perennial plants, since a perennial need only be infected by a disease once, after which the specimen may have to live with the disease indefinitely.

In contrast to vertical resistance, horizontal resistance can be achieved by the following low-cost, low-tech means:

• Growing a large, diverse, non-hybrid population
• Encouraging cross-pollination
• Not particularly discouraging pests or diseases
• Saving seed from the best performers, even if (especially if) conditions are stressful

(Robinson’s book focuses on plants, but it seems to me that the same logic would apply to animal breeding as well.)

The beauty of the process is that you don’t need to know how the horizontal resistance is achieved for it to work. You only have to see which specimens are the most successful and let them reproduce. Results may be terrible at times, but depending on how diligent and thorough you want to be, remarkable results can be achieved in as little as five generations. To really push the envelope, you can actually inoculate all individuals with a particular disease, to accelerate the process, as Robinson has done in his work with potatoes and other staple crops.

I’ve read quite a few books from various authors on gardening, farming, and sustainability. I’ve learned a great deal, and I have great respect for all those mentioned above. But if I overlay Robinson’s clearly explained concepts onto any one of these techniques, I can suddenly spot certain vulnerabilities in each. Elaborating on them would risk turning this article into a novel, so for now I’ll leave it as a thought exercise for the reader. I could speculate as to which approaches seem least susceptible, but the devil is in the details. Just as stock brokers are fond of telling clients, I think diversification is the best course.

So if you are keen to grow your own food, don’t worry about finding the One True Path to sustainability. Don’t fret over which advice to follow or how to do it perfectly. Just find something that works for you, start saving seeds and letting Nature do her best (and her worst). And if you want some clear and fascinating insights into how resistance works, I absolutely recommend you read Return to Resistance.

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