Have You Got the Energy Left?
“We” are responsible for using nearly 40% of the Earth’s production of organic matter, notwithstanding the fact that 90% of our energy needs are met by exploiting the remnants of earlier ecosystems, that is, fossil fuels. Thankfully for the sake of our backs and labour costs one gallon of gasoline can convert to three weeks of human work (38,000,000 calories or 8.8 kWh). Never the less the human body is much more efficient at converting energy to work than petrol driven machines. Oil however, is a finite energy source since we are burning it much faster than it is being formed, and as well the waste from oil fuels is damaging our other resources through pollution (not to mention driving politicians to do stupid things). This energy source will have to be replaced by a new energy source in a generation or two.
Another source of energy that is very important to farming, apart from oil but also organic in origin is organic matter in the soil. Around 5 percent in cool climates will supply sufficient biological soil activities to grow healthy crops (if the mineral nutrient levels are high enough too).
“But with the removal of water through furrows and ditches, and the aeration of the soil by cultivation, what the pioneers did in effect was to fan the former simmering fires of acidification and preservation into a blaze of bacterial oxidation and more complete combustion. The combustion of the accumulated organic matter began to take place at a rate far greater than its annual accumulation. Along with the increased rate of destruction of the supply accumulated from the past, the removal of crops lessened the chance for annual additions. The age-old process was reversed and the supply of organic matter in the soil began to decrease instead of accumulating” (William Albrecht).
Organic matter may well be considered fuel for bacterial fires in the soil, which operates as a factory producing plant nutrients. The organic matter is “burned” to carbon dioxide, ash, and other residues. This provides carbonic acid in the soil water, and the solvent effect of this acidified water on calcium, potassium, magnesium, phosphates, and other minerals in rock form is many hundreds of times greater than that of rain water. At the same time the complex constituents of the organic matter are simplified, and nitrogen in the ammonia is released and converted into the nitrate form. This, very briefly, is the complicated process of decomposition, from which carbon dioxide results as the major simplified end product, together with a host of others in smaller amounts. This gas is released in such large quantities from the soil that the supply in the atmosphere over the earth is maintained at a constant amount.
Decomposition by micro-organisms within the soil is the reverse of the process represented by plant growth above the soil. Growing plants, using the energy of the sun, synthesize carbon, nitrogen, and all other elements into complex compounds. The energy stored up in these compounds is then used more or less completely by the microorganisms whose activity within the soil makes nutrients available for a new generation of plants. Organic matter thus supplies the "life of the Soil" in the strictest sense.
When measured in terms of carbon dioxide output, the soil is a live, active body. An acre of the better Corn Belt soil in Iowa (365) or Northern Illinois, for example, exhales more than 25 times as much of this gas per day as does an adult man at work. Such a soil area burns carbon at a rate equivalent to 1.6 pounds of a good grade of soft coal per hour. A 40-acre cornfield during the warmer portion of a summer day is burning organic matter in the soil with an energy output equivalent to 40-horsepower. Every acre, in other words, may be roughly pictured as a factory using the equivalent of 1 horsepower. Organic matter is the source of the power without which the plant-food elements could not be changed to usable forms.
“We” as intelligent humans have the opportunity to adapt to our agro-ecosystem consuming available resources too quickly. Changing circumstances will, due to the loss of such energy sources, lead to an environmental crisis. One such adaptation is to improve and maintain organic matter in the soil.
