Wednesday, November 15, 2006

Effects of Conservation Tillage, Cover Crop, and Poultry Litter Application on Soil CO2 Effluxes.

Tiffany Roberson, USDA-ARS, 411 S. Donahue Dr., Auburn, AL 36832, Ermson Nyakatawa, Dept. of Plant & Soil Science, PO Box 1208, PO Box 1208, Normal, AL 35762, United States of America, and Chandra Reddy, Alabama A&M Univ., 4900 Meridian St., Normal, AL 35762.

Elevated levels of carbon dioxide from anthropogenic sources such as agriculture, use of fossil fuels, and deforestation pose environmental problems such as global warming which can negatively impact aquatic ecosystems and food production. A field study to measure carbon dioxide efflux and C storage in tilled and non-tilled cotton [Gossypium hirsutum (L.)] plots receiving poultry litter as an N source was conducted at the Alabama Agricultural Experiment Station, Belle Mina, AL in 2003 and 2004. The treatments were established in 1996 on a Decatur silt loam (clayey, kaolinitic thermic, Typic Paleudults)  soil and consisted of conventional-till, mulch-till and no-till tillage systems with winter rye cover cropping and ammonium nitrate and poultry litter sources of nitrogen. Carbon dioxide efflux in conventional-till plots which was 4.4 μm m-2 s-1 was 16% and 63%, respectively higher than that in mulch-till and no-till in 2003. In 2004, carbon dioxide effluxes in conventional-till and mulch-till were 17% and 33%, respectively, greater than no-till.  This study shows that no-till system can reduce loss of carbon dioxide from the soil into the atmosphere which may prolong soil C storage and in the long term improve soil productivity.

Handout (.pdf format, 347.0 kb)