Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/5/2004
Publication Date: 1/5/2004
Citation: Roberson, T., Nyakatawa, E.Z., Reddy, K.C., Raper, R.L. 2004. Soil co2 effluxes in conventional and conservation tillage systems with poultry litter application. National Cotton Council Beltwide Cotton Conference, January 5-9, 2004, San Antonio, Texas. Interpretive Summary: American agriculture has the potential to store additional carbon and positively impact the environment and soil productivity. A field study was conducted on a cotton-corn rotation in the Tennessee Valley Region to measure this potential carbon storage and/or loss in tilled and no-till plots that also receive poultry litter as a nutrient. Preliminary results indicate that conservation tillage systems that reduce surface tillage store carbon by reducing carbon dioxide released from the soils during tillage. Producers using conservation tillage systems in this region should have the ability to store additional carbon by using poultry litter and/or conservation tillage systems which will in turn positively impact soil productivity.
Technical Abstract: Increased levels of carbon dioxide (CO2) in the atmosphere could cause major changes in our global climate which could have a detrimental effect on world agriculture. More carbon (C) is contained in the soil than in the world's atmosphere and vegetation combined, therefore soil organic matter (SOM) plays a vital role in the world carbon balance. A field study is being conducted using existing plots and treatments established in the Fall of 1996 in a cotton [Gossypium hirsutum (L.)] and corn (Zea mays) rotated field at the Alabama Agricultural Experiment Station, Belle Mina, AL. The objectives of this study are to measure, model, and document carbon sequestration and CO2 loss in tilled and non-tilled cotton plots receiving poultry litter as a nutrient. In 2003, plots that received 100 kg poultry litter N ha-1 had total carbon values in conventional-till (CT) which averaged 22 g/kg C. No significant differences due to treatments were found in the total carbon levels in the 0-5, and 60-90 cm layers of soil. Carbon dioxide efflux values in CT which averaged 5.6 um/m-2/s-1 were 9% higher than those in mulch till (MT), 83% higher than those in no-till (NT), and 307% higher than CO2 efflux values in bare fallow (BF) plots. So far, this study demonstrates that no-till and mulch-till conservation tillage systems will sequester carbon by reducing the amount of CO2 released from soils under cotton production. This will increase soil carbon, which will in turn increase soil productivity for sustainable agriculture.