Print This PageAgriculture Can Help Keep Carbon in Balance
Ecosystems must be in balance to be able to produce healthy, abundant crops consistently. Agriculture both affects and is affected by many environmental issues that concern environmental organizations, policy-makers, and stakeholders: climate change, biodiversity, and water availability and quality.
Farmers cannot afford to be short-sighted. They need to find the best tools to achieve ever-increasing yields while protecting their topsoil, soil moisture, nutrient levels, and the environment around them.
Agricultural soils can sequester more than 10 percent of man-made carbon emissions.16
Climate change is an area of intense discussion around the world. The Intergovernmental Panel on Climate Change, an authoritative body of scientific experts, released reports in 2007 that looked at important aspects of climate change: physical science, impacts, and mitigation.13 Agriculture is inextricably affected by weather, temperature, and moisture changes thought to be caused by climate change.
At the same time, agriculture is a contributor to greenhouse gas (GHG). Worldwide, agriculture as an industry is responsible for about 13.5 percent of all greenhouse gas emissions.14 Nitrous oxide, released when fertilizer in the soil degrades, is the largest agricultural contributor to greenhouse gas.15
Agriculture has a dramatic capacity to soak up global warming gases. Worldwide, farmers have the opportunity to offset their own emissions and those of other industries.
Conservation Tillage recycles leaves, stubble, and other residue from past
crops into nutrients. As a result, it conserves soil and water, reduces erosion,
and reduces carbon dioxide released to the atmosphere.
According to the Food and Agriculture Organization (FAO) of the United Nations, “agricultural soils are among the planet’s largest reservoirs of carbon and hold potential for expanded carbon sequestration, and thus provide a prospective way of mitigating the increasing atmospheric concentration of carbon dioxide. Soils can sequester around 20 petagrams of carbon in 25 years, more than 10 percent of the anthropogenic (man-made) emissions.” 16
But
soil cannot absorb more carbon indefinitely. According to the U.S. Environmental
Protection Agency, soil carbon accumulation through conservation tillage systems
occurs for periods of 15 to 20 years. At that point, the soil reaches a carbon
steady state with no additional gains in carbon sequestration. Studies suggest
that agricultural soils in the United States, on aggregate, have not reached
a biophysical saturation point.
Rattan Lal, director of the Carbon Management and Sequestration Program at Ohio State University, believes that ultimately, carbon reductions are needed. But he says until alternative energy and more efficient transportation and manufacturing systems can be developed, which may take 50 years, soil carbon sequestration can be a cost-effective “bridge to the future.” 17
