Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 6, 2003
Publication Date: July 14, 2003
Citation: Prior, S.A., Runion, G.B., Torbert, H.A., Rogers, H.H., and Reeves, D.W. 2003. Effects of elevated atmospheric CO2 on biomass production and C sequestration: Conventional and conservation cropping systems. p. 113. In Soil Management for Sustainability, International Soil Tillage Research Organization, 16th Triennial Conference Book of Abstracts, University of Queensland, Brisbane, Australia, July 14-18. Technical Abstract: Increasing atmospheric CO2 concentration may impact production agriculture's role in sequestering carbon (C). This study was initiated (fall 1997) to compare the effects of elevated CO2 on two cropping systems (conventional and conservation). The study used a split-plot design replicated three times with two cropping systems as main plots and two CO2 levels (ambient and twice ambient) as subplots using open top field chambers on a Decatur silt loam (clayey, kaolinitic, thermic Rhodic Paleudults). The conventional system consisted of a grain sorghum [Sorghum bicolor (L.) Moench.] and soybean [Glycine max (L.) Merr.] rotation using conventional tillage practices and winter fallow. In the conservation system, sorghum and soybean were rotated and three cover crops (also rotated) were used [crimson clover (Trifolium incarnatum L.), sun hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)] using no-tillage practices. The conservation system had either cash or cover crops grown throughout the year with no fallow periods (in order of: clover, sorghum, sun hemp, wheat, and soybean). Biomass production responses over two complete cropping cycles (4 years) and the effect of these two contrasting management systems on C sequestration in the soil will be discussed.