Friday, September 2, 2016

The Soil Will Save Us by Kristin Ohlson

Photo Borrowed from Author Kristin Ohlson's Website
A Book Review By Bobbie Harte

     If you’re reading this newsletter, you already know many of the benefits of organic farming. You intuit that organic practices make tastier food, encourage biodiversity, and promote clean air and water. What you may not be aware of is that soil is connected to climate change, that land mismanagement contributes to 30 percent of the carbon emissions that enter the atmosphere, or that certain farming and land use practices may even reverse global warming. Striking the perfect chord of reality and optimism, Kristin Ohlson’s 2014 book, The Soil Will Save Us: How Scientists, Farmers, and Foodies Are Healing the Soil to Save the Planet, explores just that.
     In college, I chose Botany 101 to fulfill a five-credit science requirement. I like plants and I wanted to learn more about them, but the class was a disappointment.  We covered the biology and chemistry of photosynthesis, and we grew plants in milk containers and exposed them to different kinds of light. Sadly, I don’t remember anything else. What I really wanted from that class was something like Ohlson’s book: an exploration of the complexity of the soil and its connections to all of life. The book begins with a discussion of carbon farming and goes into the science of soil and photosynthesis. Ohlson effectively presents complicated scientific ideas in a digestible way, and she seamlessly shifts from details to the big picture. With her engaging writing style, Ohlson takes us to visit scientists, farmers and ranchers from Zimbabwe to North Dakota to Western Australia, as well as urban landscape managers in New York, Portland and Boston.
     Healthy soil prevents droughts and floods, purifies water, grows healthy food and sequesters carbon.  Soil is a collection of fungi, worms, bacteria, protozoa, nematodes, microarthropods, earthworms, beetles, voles and more. How many microorganisms are in a cup of healthy soil? “More than all the humans who have ever lived,” Ohlson writes.
     Working together, those living things create healthy soil. “Weirdly, we’ve all been schooled in the notion that plants are takers, removing nutrients from the soil and leaving it poorer,” Ohlson writes. “But when plants are allowed to work with their partners in the soil, they’re givers. They feed carbon exudates to the community of bacteria and fungi to keep them thrumming with life and pulling mineral nutrients from the bedrock as well as from particles of sand, silt, and clay….When the predator soil organisms eat the bacteria and fungi, all those nutrients are released near the plant. There’s always enough, unless human or some other force messes up the system.”
Mulch and cover crops can be an alternative
means to amend and protect soil integrity
     How can humans mess it up? Chemical fertilizer is one way. Scientists determined long ago that nitrogen, potassium, and phosphorus are essential for plant growth, and most chemical fertilizers are a combination of the three. But scientists have discovered more and more essential nutrients, and healthy soil is not a simple recipe with a list of ingredients and instructions for their combination. Plants obtain the minerals they need through complicated interactions with soil microorganisms. “Even after tilling,” Ohlson writes, “soil microorganisms will still be in the soil, but they aren’t likely to provide these varied nutrients to the plants once the chemical fertilizers are applied. Simply put, these applications interfere with one of nature’s great partnerships. By the terms of this partnership, plants …distribute carbon sugars through their roots to the microorganisms in exchange for nutrients. Fertilizer disrupts this pay-as-you-go system.”  Putting nutrients at a plant’s roots via fertilizer means the plant doesn’t have to give up any carbon to get them, and the soil organisms can’t get enough food, says Ohlson, quoting USDA microbiologist Kristine Nichols. “Without their carbon meal, the mycorrhizal fungi can’t grow and stretch their strands of carbon through the soil. They and the other soil microorganisms can’t produce the glues that fix carbon in the soil and build the aggregates that hold water. They go dormant and given enough stress, can die. At that point, the soil is so depleted of life and structure that a farmer can’t get a decent crop without chemical fertilizers….” If the relationship that makes nutrients available to plants is absent, then farmers must add more and more fertilizer each year to maintain or increase yields, which in turn creates a new set of problems. The nutrients that the plants cannot absorb runs off into waterways, where it causes algal growth. This depletes the water’s oxygen which kills aquatic life.
     As I read this book, again and again I marveled at the interconnectedness of all living things. In 2015, Robert Waldinger gave a TED Talk about the 75-year Harvard study on human happiness. Waldinger is the fourth director of this study which began with 724 men in 1938. Using questionnaires, medical records, blood tests, brain scans, interviews and more, the study continues today with 60 of the remaining men, and has expanded to include wives and some 2,000 children of the original participants. So what has the Harvard study uncovered about the secrets to human happiness? People who are more connected to family, friends and community live longer, Waldinger says. “Good relationships keep us happier and healthier. Period.” This was also the idea that stood out to me most in Ohlson’s excellent book. The key to health is relationships, whether human or microbial. Our future depends on our ability to nurture relationships, and we need to nurture them everywhere.

Note from Farmers Richard & Andrea: Soil is one of the most important components of what we do and is an essential part of life for all of us. Even after all these years of farming we continue to learn more about soil and how to care for it…..and are continually amazed by the complexity of its system. We hope you’ll consider reading this book to gain even just a glimpse into the world of soil and continue to learn along with us. In next week’s newsletter, we’ll introduce you to Sandy Syburg. Sandy is the owner of Purple Cow Organics, the company that makes our potting soil mix for the greenhouse as well as compost for our fields. Sandy is passionate about soil, loves teaching others about it and has even created a “Soil Bus” that he uses in his efforts to spread the good word about soil. He’ll be bringing the bus to our Harvest Party on September 25! See the Harvest Party Invitation sent via email for more details.

1 comment:

robertw said...

Nice review of a very important book. Thank you for pointing it out.