Understanding Carbon Cycle and Life

by Malcolm Beck

In Nature everything cycles. Tides ebb and flow, plants grow and decay, storms come and go. Summer fades into winter then spring revives the Earth once more. It is all part of the natural rhythm of life.

Man, because of his numbers and knowledge, now has the ability to alter some of these cycles. Too much carbon dioxide (CO2) in the atmosphere from burning fossil fuels has drawn the attention of scientists. Apparently this excess is causing global warming, which could change our weather patterns and drastically affect our lives. The scientists are looking to technology for answers while completely ignoring Nature's balancing processes. Nature has the answer. Why don't we consult her?

Using green plants and sunlight Nature has been sequestering carbon in the soil since the beginning. The pores, on the leaves of plants, take in CO2 and separate the carbon from the oxygen then release the oxygen to the air. Then the plants combine the carbon with hydrogen to make carbohydrates an energy source for all higher life. Eighty percent of the carbohydrates are sent to the under ground portion of the plant where it feeds a whole metroplex of beneficial soil life that live in the root zone which help the plants collect moisture and minerals to make food for itself and all higher life.

We can assist Nature in the carbon sequestering process. We have a lot of raw materials to work with. The total land area in the continental US is 1.9 billion acres. Cropland accounts for 455 million acres of that and grassland pasture is 578 million acres. When this country was first settled all the cropland and rangeland had a soil organic content ranging from 3 to 8 percent. Today the organic content of most of this land is down to less than one-fourth of what it once was. In some locations the soil organic content is down to less than two tenth of one percent.

According to Discover Magazine, humans churn out 8 billion tons of carbon dioxide every year worldwide. These 8 billion tons could be captured and put back into the soil if we operated our farms, ranches, ball fields, lawns and gardens with practices that increase and maintain the organic material in the soil.

One acre of land 6 inches deep weighs about 2 million lbs. When a soil lab does an organic matter test, they burn off the humus to determine the organic content. (In soil, everything organic will burn; the minerals just sit there. Weight loss from burning is a way to determine how much organic material exists in the soil.)

Each one percent of organic matter in the soil represents approximately 5,400 lbs. of Carbon (C). If oxidized by improper tillage and over use of chemical, carbon-free fertilizers, that amount of carbon would release to the air about 20,000 lbs.or10 tons of Carbon Dioxide. This oxidation occurs routinely with conventional farm practices.

There are many ways to help control the CO2 released into the air. Adding organic material to the soil is a very important way because so much of the land's mass is devoted to farming and ranching. If soil is mulched, rarely tilled, and has plants growing, the loss of carbon, from the soil, in the form of CO2 is dramatically decreased.

If we increased the organic content of just our cropland in the US a puny one percent we would take 4.55 billions tons (over half of what the world generates annually) of CO2 out of the air and return it to the soil. Green plants using the energy from the sun have the power to do this.

Science tells us that there are more species and more tonnage of life under ground than living above. Tilling the soil upsets this soil life and exposes it to damaging sunrays and oxidation, which releases large amounts of CO2 to the atmosphere. In a natural environment the soil with its massive amount of carbon-based roots and other soil life is rarely exposed and destroyed. Oxidation which creates CO2 does take place in a natural soil environment, but the timing and rate is governed by temperature and moisture to coincide with plant growth so the plants can capture the CO2 and re-process it instead of letting it escape to the atmosphere.

The stomata (pores) on a plant leaf are mostly on the underside, and Carbon Dioxide is slightly heavier than air, so it hovers close to the soil, easily accessible to the plant stomata. As it defuses and moves up, the plants capture it. The stomata are capable of opening and closing. When there is a concentration of CO2 near the stomata it quickly gets an ample supply, or you might say a mouth full, it doesn't need to stay open very long. Plants transpire (lose moisture) through the stomata when they are open, so a more concentrated supply of CO2 near the leaves of plants result in less soil moisture lost.

If proper soil management were taught and practiced worldwide the CO2 problems, perceived or real would become less and less. Most of the farmlands worldwide are way below the organic content they should and could be. If we would weigh the excess carbon in the air and what is missing from the soil they would be close to equal.

Research in South Texas by the USDA has shown an increase of soil organic content of one tenth of one percent each year in cropland in a no-till program. In this program all crop residue is left on the soil surface to serve as mulch, which regulates soil temperatures, and traps rain water and protects the soil from the hot sun and drying wind. Ranchers operating by Holistic Resources Management methods and organic gardeners and farmers that apply compost and mulch also see the organic soil content go up and experience moisture savings.

Building the organic content of all soils, worldwide, would also help solve the real and imminent problem of water shortages. The higher the soil organic content, the easier the annual rains can penetrate the soil. This prevents flooding, brings up the level of the aquifers and keeps the springs and rivers flowing.

In an organic rich soil, water is safe from evaporation. Trapping run off water in lakes is a poor answer to water shortages. In lakes water evaporates away — the amount depends on local environment. In central Texas the evaporation rate is around 55 inches per year.

Seventy-four percent of the Earth is covered with water, but only three percent is fresh and 80 to 90 percent of that fresh water is used for irrigation. Organic matter in the topsoil helps it hold a greater amount of water which can lessens the need for irrigation. Tests have shown up to 70 percent less in some cases.

Organic matter in the soil reduces the need for fertilizers by holding the nutrients in a non-leachable form, making fertilizers less polluting and more efficient. Plants grow healthier with more production, and less need for pesticides.

Re-cycling all waste could help do this. Bio-solids and most of the organic waste that is filling up our landfills should be composted to pasteurize and detoxify them. Then recycled back to the land. Building soil organic content is the answer to big problems mankind faces today. Health problems, air pollution, water pollution, food shortages, water shortages and floods are major problems worldwide.

But, Nature can fix them. No new technology is needed. In a natural environment there is no waste, everything is returned to the soil. Recycling and stop oxidizing the soil with over tillage are simple and viable answers.

Environmental problems, worldwide, can be solved by understanding and working with the carbon cycle on our farms, ranches, gardens and landscapes.