Friday, December 14, 2012

Save Your Soil and the Planet

    Global warming is a complicated problem with many different aspects to be considered.  A number of the aspects involve things related to the site.  Planting trees, for instance, can help to capture excess carbon that has been released into the atmosphere.  Soil is another major factor in the complicated issues of carbon.
     Soil contains huge amounts of carbon.  In a natural state, carbon builds up in the soil from the deposit of plant material on the soil surface from natural functions like leaf and stem drop and tree fall.  This organic matter is broken down and carried into the upper layer of the soil, otherwise known as the topsoil, through the activities of soil macrobes and microbes.  In fact, the top couple of feet of soil contains three times the amount of carbon that is held in the atmosphere.  In the soil, this carbon helps to enhance plant growth.
     Unfortunately, this carbon is easily disturbed and released causing increases in the atmosphere.  Disturb the soil and/or remove the permanent cover and the organic matter that holds this carbon is more accessible to breakdown by soil macrobes and microbes. They then release the excess carbon into the air in the form of carbon dioxide.
     This phenomenon has been observed for centuries.  The great cedars of Lebanon that were so highly prized by the Phoenicians were massively harvested and hauled away.  The land did not recover and regrow.  Instead, places that were denuded very quickly lost soil fertility and the ability to support regrowth.  The same phenomenon has been observed in Central and South America.  Areas that are cleared of trees for agriculture or other uses very quickly become barren and incapable of supporting regrowth.  The carbon in the soil is rapidly broken down and then lost to the atmosphere as carbon dioxide.  The soil becomes hard and devoid of fertility.  Reforestation becomes a slow and difficult process that requires a good deal of outside organic matter because it is no longer available naturally on the site.
     Soil erosion is an even greater problem.  Not only is the organic matter more exposed to breakdown, but what might remain is easily lost to downstream flowing water and spread into areas where it is least needed.  Soil left behind is often that layer below the topsoil layer.  This layer is devoid of carbon and does not easily support plant growth.  Thus, stabilizing the soil again requires the import of organic matter onto the site.
     Unfortunately, people disturb the soil in a number of ways.  They remove trees in order to harvest the lumber, clear land in order to farm and raise livestock and clear land for urban growth.  All of these activities act to release carbon into the atmosphere.  All of there activities also act to render the soil incapable of easily supporting plant growth which is a major way to capture carbon released into the atmosphere.  A vicious cycle of carbon loss ensues.
     Planting a tree, or grass or some other cover for the soil is a major defense against global warming.  Obviously, not producing greenhouse gasses is the primary defense, but not allowing them to be lost to the atmosphere from the soil is also a big part of the picture.  Those plants that cover and protect the soil not only help to capture carbon from the air; they also work to help prevent it from being removed from the soil into the air.  So, if you want to help reduce global warming go out and protect your soil.  Plant it with something!  Better still, add compost (which contains lots of carbon) and then plant it with something!

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