Healthy soil and sustainable growing

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The virtues of soil
http://rodaleinstitute.org/20080612/n1
By Melinda Hemmelgarn, M.S., R.D.

Photo © Dan Hemmelgarn
Melissa Hemmelgarn with tomatoes.

Sir Albert Howard appreciated the virtues of soil. That’s "soil," as in your 
basic garden-variety earth that many of us treat like dirt. The British 
botanist believed that humus-rich soil, the miraculous medium from which our 
nourishment springs forth, pulsates with life and forms the basis of public 
health. In the 1940s, Howard said: "The real arsenal of democracy is a 
fertile soil, the fresh produce of which is the birthright of nations."

Today, many scientists agree with Howard’s groundbreaking idea that soil 
microorganisms are the unsung heroes of healthy environments. Earthworms, 
bugs and the millions of microbes in a single handful of soil break down 
organic matter, such as leaves, decaying plants and animal manure and release 
the nutrients plants need for optimum growth.

Native farmers in Barbados and India taught Howard about the critical nature 
of soil and the interdependence of soil, plants, animals and humans. Think of 
it this way: We need healthy soil to produce nourishing food, which protects 
the health of animals and people. Healthy people create vibrant communities.

Howard realized decades ago that chemical fertilizers and synthetic 
herbicides and pesticides deplete the soil, which leads to public health 
problems, including disease and environmental destruction. Yet according to 
the National Pesticide Use Database, in 2002 more than 675-million pounds of 
pesticides were applied to crops in the United States alone.

Thankfully, the University of Kentucky Press has recently reprinted Howard’s 
The Soil and Health. Originally published in 1945, the book largely inspired 
our modern-day organic movement.

The time has come to re-think Howard’s words, especially in light of recent 
research showing what’s in organically grown food might matter as much as the 
missing synthetic pesticide and herbicide residues. For example, research at 
the University of Minnesota and the University of California-Davis found that 
organic farming methods yield produce with higher levels of nutrients, 
especially over time, as soil has a chance to accumulate organic matter. 
Researchers compared tomatoes harvested over a 10-year period from two 
matched fields, one organic and the other conventional (which included 
commercial fertilizers).

Over time, health–protecting antioxidants, called flavonoids, increased 
significantly in the tomatoes grown in the organic fields but not in the 
conventionally grown tomatoes. The researchers explained that higher quality 
soils cycle nutrients more efficiently, making them more available to plants 
when they need them. Other studies have found higher levels of vitamin C, 
iron and magnesium in organic crops, lower levels of potentially harmful 
nitrates and better taste. In general, organic production methods can raise 
healthful antioxidant levels in fresh produce by about 30 percent.

The benefits of soil-enhancing organic farming methods extend beyond 
nutritional composition. For example, at Iowa State University, horticulture 
and agronomy researcher Kathleen Delate discovered higher yields, increased 
profitability and steadily improved soil quality in organic over conventional 
fields. Improved soil structure protects against erosion and improves the 
soil’s ability to hold onto water during a drought. The United Nation’s Food 
and Agriculture Organization recommends organic farming to help fight hunger 
and tackle climate change.

Unfortunately, we tend to progress in a linear fashion, without reflecting on 
the wisdom published or spoken decades before us. Andrew Kimbrell, director 
of the Center for Food Safety and author of Fatal Harvest: The Tragedy of 
Industrial Agriculture, suggests we question that approach. "When we speak of 
progress, we should ask ourselves: Progress towards what?"

Today’s conventional agribusiness has replaced agriculture, leading us down a 
narrow and dangerous path toward shrinking biodiversity, weakened resilience 
and unhealthy soil and water. Luckily for us, the recent groundswell of 
organic demand might save our soil and our society.

Melinda Hemmelgarn, M.S., R.D., is a registered dietitian, advocate for 
sustainable food systems, and Food and Society Policy Fellow. She’s based in 
Columbia, MO. ©Food Sleuth 2008 .