314-4 Growth and Nitrogen Fixation of Two Soybean Cultivars Under Elevated Carbon Dioxide In Semi-Arid Region of Northern China.



Wednesday, October 19, 2011: 10:50 AM
Hilton Palacio del Rio, Corte Real DEF, Concourse Level

Shu Kee Lam1, Xingyu Hao2, Erda Lin3, Xue Han3, Rob Norton4, Arvin Mosier1, Saman Seneweera1 and Deli Chen1, (1)University of Melbourne, Victoria, Australia
(2)College of Agronomy, Shanxi Agricultural University, Taigu 030801, Shanxi, China
(3)Key Laboratory of Ministry of Agriculture on Agro-environment and Climate Change, Agro-Environment and Sustainable Development Institute, Chinese Academy of Agricultural Sciences, Beijing, China
(4)International Plant Nutrition Institute, Horsham, Australia
The effect of elevated carbon dioxide concentration [CO2] on symbiotic nitrogen (N2) fixation by soybean under open-air conditions has not been reported. Two soybean cultivars (Glycine max (L.) Merr. cv. Zhonghuang 13 and cv. Zhonghuang 35) were grown to maturity under ambient (415 ± 16 mmol mol–1) and elevated (550 ± 17 mmol mol–1) [CO2] at the Free-Air Carbon dioxide Enrichment (FACE) experimental facility in a semi-arid region in northern China. Elevated [CO2] increased above- and below-ground biomass by 17% and 16%, respectively, but had no significant effect on the tissue total N and total C concentration at maturity. Elevated [CO2] marginally increased the percentage of N derived from the atmosphere (%Ndfa, estimated by natural abundance) from 59 to 79% for the above-ground parts of Zhonghuang 13, and the amount of N fixed from 1.1 to 1.9 g N plant–1 (16.6 to 27.5 g N m–2), but had no significant effect on either parameter for Zhonghuang 35. It appears that impact of elevated [CO2] on N2 fixation of soybean in this semi-arid region is cultivar dependent and that these differences could be exploited to improve N supply in these cropping systems in future high carbon dioxide atmospheres.

 

Keywords

Free-air carbon dioxide enrichment (FACE), symbiotic nitrogen fixation, nodulation, natural abundance, soybean cultivar

See more from this Division: ASA Section: Global Agronomy
See more from this Session: General Global Agronomy: II