
Book: Cropland Helps Control CO2 and Ease Greenhouse EffectBy Hank Becker September
29, 1998A new book by USDA and university scientists sheds fresh light on
agriculture's potential to help offset the projected greenhouse effectglobal
warming from increasing carbon dioxide and other greenhouse gases in Earth's
atmosphere. The authors, experts in soil science, conclude that better farming practices
could sequesterremovemuch more carbon dioxide from the atmosphere
than they now do. Instead, more carbon would be stashed in the soil to benefit
crops and the environment. The Potential of U.S. Cropland to Sequester Carbon and Mitigate the
Greenhouse Effect (128 pages, Ann Arbor Press, Chelsea, Mich.) was written
by four soil science experts. They are J. M. Kimble of USDA's
Natural Resources Conservation Service,
R. F. Follett of USDA's Agricultural
Research Service, R. Lal at Ohio State
University at Columbus, and C.V. Cole at
Colorado State University at Fort
Collins. Crop plants remove carbon dioxide from the atmosphere by photosynthesis as
they grow. After harvest, leftover stalks and other residue that get
incorporated into the soil decay to become organic carbon. Farming methods that
increase soil carbon, such as conservation tillage, result in less carbon
dioxide being returned to the atmosphere as a greenhouse gas than with previous
tillage methods. Conservation tillage systems are predicted to sequester around 500 pounds
per acre per year more soil organic carbon than do plow tillage systems,
according to Follett, with ARS' Soil
Plant Nutrient Research Unit in Fort Collins, Colo. Soil erosion from U.S.
cropland soils was assessed to result in the release of about 16 million tons of
carbon a year to the atmosphere as carbon dioxide. Raising soil organic carbon levels could have many spinoff benefits: higher
crop yields over the long term, increased soil quality, less erosion, better
soil tilth (an indicator of soil health), higher farm income and improved water
quality. ARS is USDA's chief scientific agency. Scientific contact: Ronald F. Follett, ARS Soil Plant Nutrient
Research Unit, Fort Collins, Colo., phone (970) 490-8220, fax (970) 490-8213, [email protected];
John M. Kimble, NRCS
National Soil
Survey Center, Lincoln, Neb., phone (402) 437-5376, fax (402) 437-5336,
[email protected]. U.S. Department of Agriculture | |