Wednesday, February 15, 2012

Soil Symbiosis

Last winter, with its endless snow and biting cold, offered a glimpse into life in the tundra.  Certainly, as February rolled around this year, with its 50 degree F days and warm sunshine, it felt a little strange.  Something was off.  It was not normal to be without the residual strata of snow, the 5-foot-long icicles pointing precariously from the roof of Montgomery, and the small pond at the entrance to Brooks that formed as students would kick the snow from their boots.

Ice dunes on Lake Erie from Winter 2011

Now that the typical, wintery weather has finally arrived, I am already anticipating springtime.  Call me "impatient," but the thought of lush, green woods, chilly Pennsylvania lakes, and cloudless skies is absolutely appealing.  Mostly, I am looking forward to gardening.

Planting a vegetable garden has been an annual practice for my family.  As a little kid, I would use use my judgement to pick the best looking leaves of lettuce from the raised-bed garden, and make a salad for my parents, sister, and me.  After a tiring day of swimming and playing on the swing-set, my sun-burned friends and I would pick through the garden in search of cool, ripe peas in the pod.  Perhaps the fond memories have nurtured my ongoing love for the garden.  Or, more simply, I enjoy anything that combines two things that I love:  food and plants.

Garden at Allegheny

In addition to the complete satisfaction that comes with growing a variety of plants and cooking the resulting fruits, I now feel compelled to garden for more substantial reasons.  After Michael Pollan first introduced me to the unfavorable side effects of conventional agriculture, I feel a responsibility to limit my dependence on industrial agriculture and enhance my relationship with the food that I consume.  As Pollan asserts, “You are what you eat is a truism hard to argue with..."

Certainly, modern agriculture is designed to feed an enormous number of people while keeping prices "low."  As Pollan mentioned in The Omnivore's Dilemma, "Americans spend less than 10 percent of their income on food, less than the citizens of any other nation."  But, despite the low cost of food in the supermarket, other externalized costs emerge from conventional agriculture in the form of environmental problems like water scarcity and pesticide runoff.

To highlight a few major adverse effects of current agricultural techniques:

-Cultural eutrophication occurs when excess fertilizer flows into large bodies of water.  The nitrogen-rich chemicals foster overly abundant algae growth, which limits the amount of sunlight, oxygen, and space available to other organisms.  The limited resources often lead to "dead zones," as anoxic conditions cause many species to die.  Furthermore, these conditions allow anaerobic (and often, toxin-producing) bacteria (like C. botulinum, whose waste is responsible for botulism) to thrive.  The most remarkable dead zone lies in the Gulf of Mexico, where a barren 8,543 square miles are severely lacking aquatic life.
-Pesticide runoff that enters water systems can affect aquatic ecosystems, including populations of frogs and bees
-Soil erosion can be observed as soil becomes looser and nutrient deficient as a result of over-harrowing land, among other poor agricultural practices.
-Pesticides are often toxic to humans. (Monitor, Furadan are two commonly used pesticides).  Each year, millions of people experience pesticide poisoning, especially in developing nations.

"In addition to contributing to erosion, pollution, food poisoning, and the dead zone, corn requires huge amounts of fossil fuel - it takes a half gallon of fossil fuel to produce a bushel of corn." - Michael Pollan.

Well, this is overwhelming.  

Agricultural societies have been around for about 8,000 years now.  Clearly, the methods of industrial agriculture that we use now are not necessary to grow crops, but rather, to grow more, faster.  But I digress.

Growing personal gardens can alleviate our reliance on industrial agriculture.  We can support ourselves by growing some of our own food, and thereby decrease the demand that is put on the industry.   Personal gardens also limit soil erosion in populated areas, as plant root networks physically strengthen the soil and keep it from easily being diminished by wind and water.

Moreover, personal gardens need not require the applications of excessive fertilizers, pesticides and herbicides that are harmful to humans and other ecosystems.  In fact, letting plants establish symbiotic relationships with organisms in the soil is ideal. Arbuscular mycorrhizal fungi (AMF) live in the soil, on the roots of plants.  The fungi extend farther than the plant roots, and deliver essential nutrients, like phosphorus, to the plant.  In exchange, the plants sink some carbon (in the form of sugars made during photosynthesis) down to the AMF.  So, when planting a garden, consider purchasing some AMF instead of a fertilizer.

Relationship between AMF and plants, via

Planting your own garden provides the satisfaction of cultivating and cooking something you made, essentially, from scratch.  Opting to add AMF to the soil in place of chemical fertilizers lets a natural symbiosis make your garden more fruitful, and not at the expense of other ecosystems. 

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