Belize City, June 15th, 2015: The top 2 inches of soil is the source of all living things on planetEarth; it’s where all the foods that sustain animal and human life come from. Over the last 50 years as we turned agriculture from being primarily based on biology to an industry based onchemistry, we have been steadily destroying our precious top soil.
Soil begins with rock, sand, or river sediments and when mixed with organic matter becomessoil. It takes several hundreds of years to create soil but we can destroy it in 20 to 50 years with toxic chemicals and bad plowing methods. The good news is that humans can create soil inabout 3 to 5 years’ time.
Carbon and microbes work together. One needs the other. Good or healthy soil is about 50%solids and the other 50% is water and air.
One very important fact is carbon can never be created or destroyed. It changes form. When weuse certain chemical fertilizers, or do bad plowing of our fields, we drive carbon out of the soil.
Where does it go? Into the atmosphere as carbon dioxide (CO2). We need to be careful with CO2because it’s absolutely necessary for plant growth. In fact if CO2 is less than 340 parts per million (ppm) plants do not grow. And at 600 ppm, plants grow like crazy, and over 3,000 ppm CO2kills plants. But over 400 ppm CO2 may cause the earth to warm-up causing climate change, so we need a balance. While we hate to admit it, the major cause for excess CO2 in our atmosphereover the last few years has been our practicing agriculture as an industrial activity, instead of the biological activity that it is.
A very important fact that most farmers don’t understand is that when the soil is very low incarbon, the soil will not hold water. The water will run off, causing erosion, sending valuable minerals into rivers and eventually into the oceans. Also, the soil will be hard and compact.
Old leaves, dead animals, compost, and other sources of carbon supply the microbes withorganic matter without which the microbes cannot survive. It is said that one tablespoon of soil contains about 50 billion microbes. No microbes, no plants. It is the soil microorganisms whichare key in making nutrients available to the roots of plants. Soil microorganisms are crucial to several processes in agriculture. They release essential nutrients and carbon dioxide. They causenitrogen fixation, the nitrogen and phosphorus cycles, plus denitrification and mineralization.
Not all chemical fertilizers are bad. A commercial fertilizer is really a concentrated form ofenergy. And remember, energy is what causes plants to grow. However, nitrogen (N), phosphorus (P), and potassium (K) cannot supply adequate energy to plants. Plants need over80 minerals, some in very tiny amounts, while other minerals such as calcium are needed in large amounts up to over 3,500 lbs. Per acre. The key is the amount and the ratios between themajor 22 minerals. Some natural fertilizers like soft rock phosphate supply over 60 of the necessary minerals in the correct ratios.
A final note: soil breathing occurs when the calcium:magnesium ratio is adequate. This ratiodetermines the gas exchange in the soil. The better a soil can take in oxygen and then release CO2 for photosynthesis, the better will be the health and the yield of the crop or plant.