Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/28/2006
Publication Date: 8/28/2006
Citation: Prior, S.A., Runion, G.B., Torbert III, H.A., Rogers Jr, H.H. 2006. Effects of atmospheric co2 enrichment on crop nutrient dynamics under no-till conditions. In: Sustainability - Its Impact on Soil Management and Environment, Proceedings of 17th International Conference of the International Soil Tillage Research Organization, August 28 - September 3, 2006, Kiel, Germany. p. 1148-1153. Interpretive Summary: The majority of reports in the literature regarding CO2 effects on plant nutrient characteristics have been conducted under non-field conditions while this work was based on a 3 yr field study. In general, plant nutrient content was increased while nutrient tissue concentration declined under high CO2. Sorghum followed the general pattern of increased nutrient use efficiency under high CO2 more than the soybean crop while the opposite was observed for nutrient uptake efficiency. Noted deviations from the general trends in the literature may be a result of the more realistic environmental and growth conditions in our study. It is important to note that this study was based on analysis of senesced plant material while others have generally used green tissue.
Technical Abstract: Increasing atmospheric CO2 concentration could increase crop productivity and alter plant nutrient dynamics which may impact nutrient management in future CO2-enriched agroecosystems. This study was conducted in 1992, 1993, and 1994 as a split-plot design with two crop species ([Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench.]) as the main plots and two CO2 levels (375 and 705 ppm CO2) as subplots using open top field chambers in Auburn, AL. The soil was a Blanton loamy sand (loamy siliceous, thermic, Grossarenic Paleudults) and no-till management was used in all plots. At the end of each growing season, plants were separated into component parts prior to dry weight determination and nutrient analysis. Carbon dioxide-induced changes in nutrient dynamics for these crops will be discussed in terms of nutrient concentration, nutrient content, nutrient utilization efficiency and nutrient uptake efficiency.