Book Review: Teaming With Bacteria by Jeff Lowenfels
Plants eat bacteria. This discovery, made possible by recent advances in microscope technology, is rewriting fundamental assumptions about how plants acquire nutrients and how best to care for them. Everything from the way seeds are started, to how pests and weeds are managed, to the application of fertilizers is currently being reevaluated or soon will be. In Teaming with Bacteria, America’s longest running garden columnist, Jeff Lowenfels, introduces the world of rhizophagy (literally “root eating”). In doing so, he invites readers to fundamentally reconsider their relationship with the untold trillions of microbial allies lying just beneath their feet.
Lowefels’ previous three books brought the concept of the soil-food-web (the symbiotic networks between plants, microbes, fungi, and other constituents that make up healthy soil) into the popular imagination and are considered required reading for organic gardeners and commercial growers. Each described in cheerful detail how plants actively attract and cultivate communities of desirable microbes through the exudates produced by their roots. These microbes in turn make nutrients available for the plant, either by their own devices or as they are consumed and broken down by larger microorganisms in the soil. Lowenfels demonstrated how widespread practices like rototilling and the application of synthetic fertilizers and pesticides decimate these networks, degrade soil, and render plants more susceptible to disease at massive economic and environmental expense. Better to feed the soil, he argued, through organic practices including the application of compost, cover crops, managed grazing, and companion planting.
In Teaming with Bacteria, this model of the soil-food-web is transformed. The latest advances in microscope technology have revealed that, when it comes to bacteria, plants aren’t merely microbe farmers. They also act as shepherds that herd bacterial flocks into the endophytic spaces within and between root cells. There, plants produce enzymes that sheer their bacterial flock of their cell walls, causing them to release nutrients and their own defensive compounds that spur the growth of root hairs from which they are ultimately expelled back into the rhizosphere to replicate and repeat the cycle.
The implications of this rhizophagy cycle are wide ranging. Lowenfels surveys the emerging body of scientific literature on the subject and offers the reader a tantalizing selection of its applications. In one notable finding, a study found that using a rhizobia inoculant can reduce commercial nitrogen requirements by 25%. The list goes on. Endophytic bacteria products may be the key to saving bananas, increasing the level of vitamin B12 in lettuce, improving corn yields in Africa by enabling corn to outcompete a voracious weed, increasing potato yield, coating seeds for turf and other grasses to promote growth and reduce pressure from weeds, increasing the nutritional value of barley, helping trees ward of bark beetles, and helping cannabis plants produce phytocannabinoids (the highly desired compounds that give cannabis its infamous aroma and psychoactive effects).
These findings are being replicated and applied to products that will soon be available in every neighborhood garden store. And not a moment too soon. Agriculture accounts for roughly a quarter of global greenhouse gas emissions, the bulk of which can be traced to the ubiquitous application of pesticides and synthetic fertilizers. These carbon intensive techniques are eroding topsoil at a rate that threatens to eliminate arable land within latter half of this century. Meanwhile, agricultural yields must increase by 60–70% by 2050 to feed the growing global population.
One of the most exciting implications of Lowenfels’ work is that the dual necessities of agricultural decarbonization and increasing yields need not be at odds. The transition to regenerative techniques that enhance the rhizophagy cycle and draw carbon dioxide from the air into the soil could also be the key to unlocking sustainable, abundant, and healthier food.
In Lowenfels’ telling the role of the gardener is not to replace the soil food web, but to sit in wonder before it and learn to facilitate it. His writing blends hard science, practical application, advocacy, and good cheer in equal measure (behold, the joy of bacterial flagella!). His writing invites awe and compels action. Plants are very, very good at partnering with their microbial minions to get exactly what they need, when they need it. Bacteria are both ubiquitous and essential. It is difficult to name a single facet of life that these tiniest of organisms don’t impact. Lowenfels proves once again to be an incomparable guide to the intersections between their worlds and our own. Teaming with Bacteria is a remarkable read. It will serve as an essential reference for organic gardeners and all those who find joy in helping plants grow.
