THIS author is down to earth in every sense. David Montgomery, a research geologist at the University of Washington, is one of our most eloquent and precise earth science communicators. In his latest book, he takes on one of the toughest problems contributing to climate change and resource depletion: the impoverishment of the soil. On top of being a catastrophe in itself, the collapse of the soil microbiome also impairs its capacity to sequester carbon and retain moisture.
Montgomery visits farmers, range managers and others who set out to show that improving the diversity and resilience of the soil microbiome can be economically viable and have a lasting ecological impact. This point has been made before, in Courtney White’s Grass, Soil, Hope and by Eric Toensmeier in his practical guide The Carbon Farming Solution. Montgomery’s meticulous scientific research deepens the discussion, reviewing the recent technical literature to explain and evaluate farmers’ claims.
Montgomery is one of the most prolific science writers in the US, and sometimes that industriousness takes its toll. For my money, the best book ever written on the fungi, nitrogen-fixing bacteria and insects that run the world from beneath our feet is The Hidden Half of Nature, which Montgomery co-wrote with his wife. In contrast, these latest journalistic accounts of visiting “carbon farmers” and “carbon cowboys” around the world feel a little thin.
Much of value remains. Montgomery steers clear of the suggestion that there is a single biotechnological fix to soil ecology – a one-size-fits-all approach like Allan Savory’s managed grazing or Wes Jackson’s “natural systems agriculture”. He looks instead for a mix of tactics, which will be applied in different proportions to fit different landscapes.
“We can restore beneficial microbes to our skin, might we really perform the same feat for the soil?”
If there is any flaw in Montgomery’s scientific assessments, it may lie in his optimism. He has high hopes for annual crops, though many ecologists think they are ecologically quite damaging. It is hard to imagine that any annual herbaceous crop could sequester much carbon, compared with longer-lived perennial crops in the same settings. “Food forests” of fruit and nut trees, or even deep-rooted grasses and other herbaceous crops do far less damage to the soil because they require less tillage.
The effort that farmers of annual crops expend to make their operations more sustainable are noble. But I’m wary of any hype, never mind whether it comes from the biotech industry or the biodynamic farm movement, suggesting that annual crops can be as ecologically sound and mitigate climate change as effectively as orchards and perennials.
If Montgomery is indeed “growing a revolution” then his next steps are clear, and it will be fascinating to know whether some of the suggestions he floats before us will bear fruit. Might future agricultural systems be able to apply lessons drawn from elsewhere in biology to solve our current agricultural crisis? Montgomery explains how microbial ecologists working in hospital operating rooms are learning to reverse the devastation caused by antibiotics, and restore beneficial microbes to our skin and gastrointestinal tracts; might we really perform the same feat for the soil?
Montgomery has a knack for opening our minds to large, critically important questions. Plausible answers to those questions can be slow in coming, and this can be frustrating. But that, to my mind, is why we need more risk-takers like Montgomery in our midst.
W. W. Norton
This article appeared in print under the headline “Don’t desert the earth”
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