Soil nitrogen transformations under elevated atmospheric CO2 and O3 during the soybean growing season

• Published in: Environmental pollution (1987) Vol. 159; no. 2; pp. 401 - 407
• Main Authors: Pujol Pereira, Engil Isadora, Chung, Haegeun, Scow, Kate, Sadowsky, Michael J., van Kessel, Chris, Six, Johan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.02.2011; Elsevier
• Subjects: Abundance; Air - analysis; Animal, plant and microbial ecology; Applied ecology; Bacteria - genetics; Bacteria - isolation & purification; Bacteria - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological and medical sciences; Biotransformation; Carbon dioxide; Carbon Dioxide - analysis; Carbon Dioxide - metabolism; Denitrification; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Elevated; FACE; Fundamental and applied biological sciences. Psychology; Glycine max - growth & development; Glycine max - metabolism; Glycine max - microbiology; Minerals; Nitrates - metabolism; Nitrification; Nitrogen - metabolism; Ozone - analysis; Ozone - metabolism; Plants (organisms); Quaternary Ammonium Compounds - metabolism; Real-time quantitative PCR; Seasons; Soil (material); Soil - analysis; Soil Microbiology; Soil N cycling; Soybeans; Transformations; USA, Illinois; Real-time quantitative PCR; Denitrification; FACE; Nitrification; Soil N cycling; Growing season; Ozone; Soybean; Nitrogen; Real time; Glycine max; Real time system; Polymerase chain reaction; Grain legume; Medium enrichment; Soils; Nitrogen cycle; Leguminosae; Dicotyledones; Atmosphere; Angiospermae; Spermatophyta
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2010.10.033

We investigated the influence of elevated CO2 and O3 on soil N cycling within the soybean growing season and across soil environments (i.e., rhizosphere and bulk soil) at the Soybean Free Air Concentration Enrichment (SoyFACE) experiment in Illinois, USA. Elevated O3 decreased soil mineral N likely through a reduction in plant material input and increased denitrification, which was evidenced by the greater abundance of the denitrifier gene nosZ. Elevated CO2 did not alter the parameters evaluated and both elevated CO2 and O3 showed no interactive effects on nitrifier and denitrifier abundance, nor on total and mineral N concentrations. These results indicate that elevated CO2 may have limited effects on N transformations in soybean agroecosystems. However, elevated O3 can lead to a decrease in soil N availability in both bulk and rhizosphere soils, and this likely also affects ecosystem productivity by reducing the mineralization rates of plant-derived residues. [Display omitted] ► Elevated O3 promotes accumulation of total soil N. ► Ammonium concentrations under elevated O3 were lower than those under ambient conditions. ► Elevated O3 may increase mineral N losses through the increase of denitrification. ► Elevated CO2 did not affect soil mineral N and total N concentrations. Our findings indicate that although elevated CO2 increases plant biomass, N transformations were minimally affected. In contrast, elevated O3 decreased soil mineral N likely through a reduction in plant material input and increased denitrification as indicated by the greater abundance of the denitrifier gene nosZ.