Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 19, 2007
Publication Date: February 6, 2007
Citation: Nichols, K.A. 2007. Carbon Energy Flows Belowground. Meeting Proceedings for the 29th Annual Zero Tillage and Winter Wheat Workshop, Brandon, Manitoba. Feb. 5-7. pp. 1059-1161. Technical Abstract: Plants use photosynthesis to convert carbon dioxide in the atmosphere and energy from sunlight into energy-containing, carbon-based foodstuffs (i.e. carbohydrates such as sugars and starches) that provide the building blocks for all life on Earth. Without photosynthesis, sunlight would not be a good energy source because it cannot be eaten, do work, or be stored (cheaply). With photosynthesis, the sun’s energy is stored in food that may be consumed. When food is consumed by us or any other organism, it is oxidized or “burned” by combining it with oxygen from the air. This burning produces energy, carbon dioxide, and other carbon-based molecules that may be used by other organisms to produce energy. Carbon enters the belowground foodweb as organic substances (i.e. molecules that contain carbon, hydrogen, and oxygen) derived from aboveground photosynthesis. These plant residues, which may be made up of leaves, roots, stems, fruits, or exudates, are used either directly or indirectly by all of the micro- and macro-organisms in the foodweb. Microbes such as bacteria, fungi, microarthropods, protozoa, and nematodes feed directly on plant residues as do larger organisms such as insects and earthworms. The carbon and energy containing waste products produced by these organisms are the food for other soil-based organisms and micro-organisms. This process continues through different organisms until no more energy is biologically available from the carbon compounds. The flow of carbon-based energy belowground impacts: 1. the food we eat by improving soil quality and nutrient cycling, 2. the air we breathe by acting as both a sink and a source for carbon dioxide, nitrous oxide, methane, and other atmospheric gases, and 3. the places we live by providing an energy source, construction material, a stable foundation, etc. Therefore, the organic and biological component that separates soil from dirt also separates life from lifelessness on our planet.