“Frankly those soil maps of the world that show its degradation do depress me, but they also hold the seeds for optimism,” says David R Montgomery, MacArthur Fellow, professor of geomorphology at the University of Washington and keynote speaker at the Agri-TechE REAP conference on 10th November 2020.
“For while there is much work to do, there is much to be gained by doing it. Investing in rebuilding healthy, fertile soils is one of the best investments humanity could make in our collective future.”
The theme for REAP 2020 is “From micro-scape to landscape – innovating at the frontier”. Soil is a good example of how new methods are needed both to see the whole picture and also to manage the fine details.
Through investigations at every level David Montgomery believes that it really is possible to change the world from the ground up. He says in his book “I find it fitting that the words humus and human share the same Latin root, restoring healthy soils is the best investment we can make in humanities future. So as we grapple with the daunting problems of feeding the world and cooling the planet, let us not lose sight of a simple truth. Sometimes the answers we seek are right beneath our feet!”
Montgomery has travelled the world, meeting farmers at the forefront of an agricultural movement to restore soil health. He sees the huge societal benefits of this work and potential for reforming government subsidies to incentive practices that build soil health and carbon storage. We asked him about this ahead of his talk at REAP.
Q. In your book Growing a Revolution you comment that “…something is seriously wrong with our agricultural system if hardworking Iowans on best agricultural soil can’t make money….” do you think reliance on subsidies is the problem?
DM. We should be using our subsidies to help ensure the economic livelihood of farmers who are good stewards of the intergenerational trust that fertile soil can, and should, be.
Subsidises take many forms, but today in the US at least, most of our subsidies discourage good stewardship of soil health. I would strongly favor reforming but not eliminating agricultural subsidies. In my view, they should be restructured from top to bottom to prioritize and incentivize practices that build soil health
Q. Taking a big picture view – you advocate a ‘soil health moonshot’, how would this help?
DM. I see the moonshot analogy as referring to harnessing social willpower to focus on rapidly achieving a goal that would seem out of reach without such focus.
I’m suggesting is that we reorient a portion of the fortune that we already spend on governmental support for agriculture and agricultural research to addressing the challenge of using intensive agriculture to restore rather than continue to degrade the world’s farm and ranch land soils.
Of course, the more funding for research and demonstration farms the faster we might pull off a major shift in practices. (And for the record, my university does not have an agriculture program so we’re not likely to benefit from this proposal!)
Q. You also propose that ‘carbon credits could provide an income stream for farmers based on societal value of carbon’, how would you see this working?
DM. I would advocate linking adoption of specific verifiable practices (like no-till and cover crops) to credits based on regionally calibrated studies to establish an expected benefit (increase in carbon content or maintenance of it in the soil). I think we need to reward farming not only for increasing carbon but for not degrading it in the first place.
Q. On the micro scale – how can farmers measure carbon and is this a good proxy for soil health?
DM. Soil health is microbial, nutritional and physical. Certainly, the simplest measure of soil health is the organic matter (carbon) content of the soil.
But soil carbon only captures one dimension— what’s there to eat in the soil – not whose there and how active they are. So you also want to know something about the microbial population — it’s abundance and diversity. That makes microbial biomass, respiration (activity), and the soil fungi-to-bacteria ratio key indicators of soil health as well. Meta-genomics can tell you a lot more about the community structure, though we’re still learning how to interpret what that means for soil health.
Q. Much of your research has been in continental or tropical climates, do you think these principles can be universally applied?
DM. Yes, one of the key takeaways for me from writing Growing a Revolution is that the principles seem to apply widely even if the specific practices need to be tailored to regional and local climate and soils.
And I’ve been on farms at the Groundswell conference in England that have successfully applied these ideas.
Q. Finally – What measures would you like to see all arable farmers take to ‘boost carbon’?
The simplest advice I can offer boils down to ditch the plow, cover up, and grow diversity. I’ve seen the recipe of minimal disturbance (no- or low-till), keeping the ground covered with living plants at all times (cover crops) and growing at least 3 or more crops in a rotation work on farms around the world. Some add innovative animal husbandry to the mix to accelerate soil building. One thing I’d like to see is more farmers tinkering with these systems to better adapt the specific practices to their on-the-ground situation.
More information about ‘Growing a Revolution’