Soil Organic Carbon and Nitrogen Accumulation in Plots of Rhizoma Perennial Peanut and Bahiagrass Grown in Elevated Carbon Dioxide and Temperature

• Published in: Journal of environmental quality 2006-07, Vol.35 (4), p.1405-1412
• Main Authors: Allen, Leon Hartwell, Albrecht, Stephan L., Boote, Kenneth J., Thomas, Jean M. G., Newman, Yoana C., Skirvin, Katherine W.
• Format: Article
• Language: English
• Subjects: Accumulation; Agricultural land; Agriculture; Agronomy. Soil science and plant productions; Applied sciences; Arachis - growth & development; Arachis hypogaea; Atmosphere; Biological and medical sciences; Biotechnology; Carbon; Carbon - metabolism; Carbon dioxide; Carbon Dioxide - metabolism; Carbon sequestration; Conservation of Natural Resources; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Grasslands; Industrial applications and implications. Economical aspects; Nitrogen; Nitrogen - metabolism; Organic carbon; Organic Chemicals - chemistry; Organic Chemicals - metabolism; Paspalum - growth & development; Paspalum notatum; Pollution; Pollution, environment geology; Soil; Soils; Temperature; Time Factors
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2005.0156

ABSTRACT Carbon sequestration in soils might mitigate the increase of carbon dioxide (CO2) in the atmosphere. Two contrasting subtropical perennial forage species, bahiagrass (BG; Paspalum notatum Flügge; C4), and rhizoma perennial peanut (PP; Arachis glabrata Benth.; C3 legume), were grown at Gainesville, Florida, in field soil plots in four temperature zones of four temperature‐gradient greenhouses, two each at CO2 concentrations of 360 and 700 μmol mol−1 The site had been cultivated with annual crops for more than 20 yr. Herbage was harvested three to four times each year. Soil samples from the top 20 cm were collected in February 1995, before plant establishment, and in December 2000 at the end of the project. Overall mean soil organic carbon (SOC) gains across 6 yr were 1.396 and 0.746 g kg−1 in BG and PP, respectively, indicating that BG plots accumulated more SOC than PP. Mean SOC gains in BG plots at 700 and 360 μmol mol−1 CO2 were 1.450 and 1.343 g kg−1, respectively (not statistically different). Mean SOC gains in PP plots at 700 and 360 μmol mol−1 CO2 were 0.949 and 0.544 g kg−1, respectively, an increase caused by elevated CO2 Relative SON accumulations were similar to SOC increases. Overall mean annual SOC accumulation, pooled for forages and CO2 treatments, was 540 kg ha−1 yr−1 Eliminating elevated CO2 effects, overall mean SOC accumulation was 475 kg ha−1 yr−1 Conversion from cropland to forages was a greater factor in SOC accumulation than the CO2 fertilization effect.