Improving Soil Health & Enhancing Food Security

“The soil is the great connector of our lives, the source and destination of it all.”

– Wendell Berry

Farmers are increasingly asked to not only provide high yields for growing populations, but also to ensure production of environmental services and nutritious foods for communities.  Current hot topics surrounding this challenge include climate change, genetic modification, water shortages, and food access.  However, a less glamorous component is often left out of this discussion that certainly merits our attention: the living soil just beneath us.  Sustainable management practices that build healthy soil systems ensure the long-term viability of lands result in healthier Appalachian soil and people.

So what is sustainability in terms of soils?  What is soil quality, and how does a farmer know if her soil is “healthy”?  Physical, chemical, and biological characteristics of the soil come together to form a complete picture of soil health, which can be measured by the stability of the soil system, the levels of biological diversity and activity, internal nutrient cycling, and resilience to disturbance.  Soil management practices impacting overall soil health include tillage, crop residues and soil surface covers, and the use of crop rotations.

The soils of Appalachia are generally high in organic matter and fertility and have a well-balanced moisture content and relatively high acidity from thousands of years of formation under dense forest.  Most are classified as Inceptisols, Ultisols and Alfisols that developed from heavily weathered shale, sandstone and transported materials from upslope.  These soils naturally provide humans with many benefits, known as ecosystem services.  Soil services include providing physical stability and support for plants, the renewal, retention and delivery of nutrients for plants, habitat to soil organisms, buffering, filtering and moderation of the hydrological cycle, and disposal of wastes and dead organic matter.  These soil ecosystem services are closely tied to water management including erosion, sedimentation, and water quality protection.

Great strides have been made in protecting ecosystem services of soil and replacing degrading practices through soil conservation practices.  Going a step further involves not only conserving, but growing improved soils over time.  There are many practices that improve the physical structure and the biological health of the soil.

The plant and animal communities of the Appalachian Mountains are famous for their incredible biodiversity, but there is a lot more going on than meets the eye helping to build healthy soil.  Though many are invisible without the use of a microscope, 90% of all organisms globally live in the soil.  There are bacteria, fungus, protozoa, nematodes, mites, and microanthropods.  A teaspoon of soil can house 10,000-50,000 species!  Soil microorganisms need good aeration, drainage and nutrients, and thus are an indicator of soil.  Like the complex ecology of microbes the human digestive and immune systems, soil microbes digest nutrients and protect plants from pests, pathogens and environmental disturbances.  A great example is beneficial fungi growing on plant roots, known as mycorrhizae.  This symbiotic relationship between the fungi and plant roots increases the water and nutrient absorbing surface area of roots and actually helps to transmit signals between plants at the onset of a disturbance.  Soil microbes, like microbes in the human body, provide resilience to our food system.  Protecting their habitat by building and conserving healthy soils is necessary to sustain or improve food security.

Another important facet of soil health is management practices that impact the physical structure of soil.  Globally, soil degradation and loss is a major issue for agriculture.  Depending on where you are in the world, between 6 and 24 pounds of arable soil are lost for every pound of food eaten.  Conventional farming methods have disturbed around 75% of U.S. lands.  This is more than natural erosion from wind, water and gravity, but rather human-induced erosion, which is defined as degradation.  Soil degradation is futher complicated in Appalachia through a combination of steep slopers and extractive industries such as mining and logging.

Sustainable practices and profitable farming don’t have to come at the expense of our natural resources.  Low-tech solutions such as cover cropping, zero or minimum tillage, planting buffers of grasses or trees at the edges of fields and along streams and the contours of hills can prevent the vast majority of this soil loss.  These simple measures also help increase the soil’s ability to filter chemicals and runoff, protecting our water sources.

Small and medium sized farms in West Virginia and the Appalachian counties of North Carolina and Virginia occupy a key position in the regional economy and food system.  These farms provide high-quality fresh foods and steward the beautiful mountain countryside.   Compared to large-scale, highly industrialized agricultural systems, small and medium scale farms offer a broader and more complex range of ecosystem services due to their integrated nature and also act as key drivers in local and regional economies.  Rates of food security and insecurity at the household level vary throughout Appalachia, but are certainly not aided by the decreasing number of farms and farmers looking after our important soil resources.  Farmers who take care to conserve and build healthy soils should be recognized and rewarded.  Learning more about the dark, exciting world underfoot and the important links between soil and human health highlight the need to support local farmers are stewards of the soil and our delicious food supply.

For more information on soil health and quality, visit the USDA National Resources Conservation Service website.

Do you have pictures of your soil you would like to share?  E-mail them to us at afp@vt.edu and we will add them to the post!

This post has been contributed by Margaret Smith, a graduate research assistant for the Appalachian Foodshed Project.  Margaret is a masters student at Virginia Tech in the Department of Crop & Soil Environmental Sciences.  She works with Dr. Steve Hodges.