Submitted to: Soil Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/1/2004
Publication Date: 6/1/2004
Citation: Prior, S.A., Runion, G.B., Torbert III, H.A., Rogers Jr, H.H. 2004. Elevated atmospheric co2 in agroecosystems: soil physical properties. Soil Science. 169(6):434-439. Interpretive Summary: Enhanced crop production under elevated atmospheric CO2 conditions, suggests greater residue inputs to the soil system. We studied how elevated CO2 would affect soil physical properties in a long-term cropping systems study managed under no-till conditions. Results indicate that greater biomass inputs increased soil carbon storage and improved soil physical properties, especially in the soybean production system. Positive shifts in soil physical properties could also reduce soil erosion and increase soil water storage, thereby increasing soil productivity in a high CO2 environment
Technical Abstract: Increased crop biomass production due to elevated atmospheric CO2 concentration suggests more carbon input to the soil which could alter soil physical properties. Soil samples were collected from the surface layer (0-6 cm) after 5 years of soybean [Glycine max (L.) Merr.] or sorghum [Sorghum bicolor (L.) Moench.] production under two CO2 levels (360 ppm and 720 ppm) on a Blanton loamy sand (loamy siliceous, thermic, Grossarenic Paleudults) under no-till management using open top field chambers in Auburn, AL. Soil carbon content, bulk density, saturated hydraulic conductivity, and water stable aggregates were measured. Soil carbon content was increased by elevated CO2. Significant cropping system by CO2 interactions were noted for soil bulk density and saturated hydraulic conductivity; aggregate stability exhibited a similar trend. In the soybean system, soil bulk density decreased while saturated hydraulic conductivity and aggregate stability increased due to elevated CO2, however, CO2 had little affect on soil properties in the sorghum system. Results indicate that greater non-yield biomass inputs could increase soil carbon content and improve soil physical properties, especially in soybean production systems.