Almost two years ago, Ellie and I attended William DeMille’s Soil Boot Camp, a phenomenal 3-day course on improving soil health and becoming able to grow food without manmade inputs, something that has been a concern of mine for many years. At the conclusion of that course, I knew I wanted to attend again, and I was able to make that happen this month.
One of the articles I wrote based on what I learned in that first course focused on using plant diversity to eliminate garden pests. Now, I didn’t plan my garden that year based on what I learned in the class because the course was held in August, long after the garden had been planted. However, what I observed that year (and in the two years since) is that plant family diversity really does reduce the number of pests in the garden. I had no aphids that first year. I had two last year, as well as two tomato worms. They were on the very edge of the garden, so that may have had something to do with it. I did not spray for any bugs at all, and I didn’t have them in my food.
Pest elimination would be reason alone to incorporate plant diversity into the garden. But what if you could also make your produce more nutritious and taste better? Wouldn’t that be a dream?
Dreams can come true.
As I mentioned Friday, garden productivity is closely tied to soil health, and specifically secondary metabolites and quorum sensing. What are these concepts?
First, let’s discuss what primary metabolites are. And because they’re still a little difficult for me to conceptualize, I’ll use a snippet from an article published in Frontiers in Plant Science.
Primary metabolites include sugars, amino acids, polypeptides, proteins, carboxylic acids, and fatty acids, have been well-characterized in the exudates of plant roots, which essentially serve as vital carbon, nitrogen, and energy sources for competitive root colonization and suppression of pathogenic soil. Apart from supporting microbial proliferation, these exudate metabolites are also responsible the formation of distinct microbial assemblages in the rhizosphere.
Now for the secondary metabolites:
Besides primary metabolites, countless secondary/specialized metabolites, generally overlooked compounds with significant bioactivities, are present in the root exudates, functioning as stimulants, inhibitors, or signaling molecules. For example, benzoxazinoids released by maize roots act as important herbivore and pathogen resistance factors and trigger rhizosphere colonization by the bacterium Pseudomonas putida. In addition, root released camalexin and coumarins can increase plant growth and positively affect root microbiota under nutrient-limited conditions.[1] (Bolding mine)
Lots of big words.
So basically, when plants from at least four different plant families are grown in close proximity (which means their roots will reach out and touch each other), it creates conditions in the soil to grow the maximum number of beneficial microbes. It fosters enough diversity and growth of the microbes that adding fertilizer becomes unnecessary. How is this possible? Scientists don’t exactly understand this yet. These different plant families, when planted in close proximity, activate something called quorum sensing and create a synergy. This quorum sensing turns on the secondary metabolites so that the plant expresses its genes better. Nutrition improves. Flavor improves. Pest and disease resistance improve.
Note that incorporating more plants from different families yields even better results. And what do you think would happen if you mixed in medicinal herbs. Would they not grow better and improve their medicinal qualities as well?
And some not-so-random thoughts.
1. A couple of our closest friends took their son and daughter-in-law to Europe for a week or two this winter. This daughter-in-law has suffered from serious eczema and other related issues for most of her life. Her father is an anesthesiologist; access to good care wasn’t an issue. She strictly controlled her diet in the US to alleviate symptoms as much as possible, but decided to ignore her diet while in Europe since it was the trip of a lifetime. Anyway, within 24 hours of arriving in Europe, all issues cleared up. Within 24 hours of returning to the US, all issues returned. As she has lived on diverse climates in the US, she can’t attribute he skin issues to changes in temperature or humidity. She and her family believe that the problem lies in our food.
2. So much of the research referenced in the herbal medicine topics is conducted in outside the US, in places that have higher standards in their agricultural practices. Would not this affect medicinal herbs as well? And what about all those herbs grown in China and then repackaged for sale in the US? How beneficial are they likely to be?
Now, more than ever, I think we need to grow our own and do everything we can to improve our soil health and become less reliant on manmade inputs.
Links to related posts:
I've been reading a book called "What Your Food Ate" which has brought me to the same conclusion about improving soil health and growing our own food. There's a lot to be said for companion planting and intercropping.
ReplyDeleteI saw that book recommended somewhere. What do you think about it overall?
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