Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/25/2006
Publication Date: 4/26/2006
Citation: Farahi, F., Cavigelli, M.A. 2006. The effects of cropping systems on the emission of carbon dioxide from soil [abstract]. BARC Poster Day. S9. Interpretive Summary:
Technical Abstract: Global warming is an arising problem which is due to an increase of greenhouse gases (carbon dioxide, methane and nitrous oxide) in the atmosphere. Agriculture can have a net positive or net negative influence on atmospheric CO2 concentrations based on the balance between C inputs to soil (via photosynthesis and subsequent addition of plant residues or animal manures) and C outputs (soil respiration and erosion). Carbon sequestration in agricultural soils, which has been proposed as a means of reducing the rate of increase of atmospheric CO2 concentration, is based on the idea that agriculture would be a net sink for atmospheric carbon dioxide if carbon inputs to soil are greater than carbon outputs. I measured soil CO2 flux to assess C outputs from three different cropping systems: an organic, a chisel tillage, and a no tillage system. Samples were taken every week to every month, depending on time of year, from April to October in 2005. Initial results show that peak CO2 flux in all three systems occurs in June, August and October. Total CO2 flux was greater in the organic system than in the two conventional systems but C inputs are also greatest in the organic system. CO2 flux was positively related to both soil moisture and soil temperature. Once all samples are analyzed, carbon outputs will be compared to carbon inputs and these results compared to changes in soil carbon after 10 years to better assess the net influence of these three cropping systems on atmospheric CO2 concentration.