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Elevated Atmospheric Carbon Dioxide and O 3 Differentially Alter Nitrogen Acquisition in Peanut
Author(s) -
Tu Cong,
Booker Fitzgerald L.,
Burkey Kent O.,
Hu Shuijin
Publication year - 2009
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2008.10.0603
Subject(s) - carbon dioxide , ozone , zoology , biology , nitrogen , arachis hypogaea , photosynthesis , nitrogen fixation , carbon dioxide in earth's atmosphere , horticulture , botany , chemistry , ecology , organic chemistry
Elevated atmospheric CO 2 and ozone (O 3 ) may affect productivity of legumes in part by altering symbiotic N 2 fixation. To investigate this possibility, measurements of plant biomass, N levels and natural 15 N abundance (δ 15 N) were used to examine the effects of elevated CO 2 and O 3 on N acquisition in field‐grown peanut ( Arachis hypogaea L.) using open‐top chambers. Seasonal 12‐h daily average CO 2 treatment concentrations were 376, 550, and 730 μmol mol −1 Carbon dioxide treatments were applied in reciprocal combinations with seasonal 12‐h daily average O 3 concentrations of 21, 49, and 79 nmol mol −1 At mid‐vegetative growth, elevated CO 2 significantly reduced leaf N concentrations by up to 44%, but not δ 15 N values. Elevated O 3 did not significantly affect N concentrations or δ 15 N values. At harvest, plant N concentrations were similar among treatments except for a 14% reduction in the highest‐level CO 2 –O 3 treatment. Plant N accumulation varied in proportion with treatment effects on biomass production, which was increased with elevated CO 2 when averaged over the O 3 treatments and suppressed by high‐level O 3 at ambient CO 2 Elevated CO 2 reduced plant δ 15 N values in low‐ and mid‐level O 3 treatments while mid‐ and high‐level O 3 increased them at ambient CO 2 The changes in δ 15 N values suggested that N 2 fixation activity was stimulated with elevated CO 2 and inhibited by elevated O 3 Elevated CO 2 ameliorated detrimental O 3 effects to varying extents depending on the concentrations of the two gases. These results indicated that interactions between CO 2 and O 3 on plant physiology can alter N acquisition processes, with impacts on peanut productivity likely dependent in part on these changes.