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Yield and nitrogen accumulation and partitioning in winter wheat under elevated CO2: A 3-year free-air CO2 enrichment experiment

Han, Xue, Hao, Xingyu, Lam, Shu Kee, Wang, Heran, Li, Yingchun, Wheeler, Tim, Ju, Hui, Lin, Erda
Agriculture, ecosystems & environment 2015 v.209 pp. 132-137
carbon dioxide, climate, combustion, deforestation, fertilizer rates, field experimentation, flowering, fossil fuels, free air carbon dioxide enrichment, grain yield, growing season, nitrogen, ripening, winter wheat, China
Fossil fuel combustion and deforestation have resulted in a rapid increase in atmospheric [CO2] since the 1950’s, and it will reach about 550μmolmol−1 in 2050. Field experiments were conducted at the Free-air CO2 Enrichment facility in Beijing, China. Winter wheat was grown to maturity under elevated [CO2] (550±17μmolmol−1) and ambient [CO2] (415±16μmolmol−1), with high nitrogen (N) supply (HN, 170kg Nha−1) and low nitrogen supply (LN, 100kg Nha−1) for three growing seasons from 2007 to 2010. Elevated [CO2] increased wheat grain yield by 11.4% across the three years. [CO2]-induced yield enhancements were 10.8% and 11.9% under low N and high N supply, respectively. Nitrogen accumulation under elevated [CO2] was increased by 12.9% and 9.2% at the half-way anthesis and ripening stage across three years, respectively. Winter wheat had higher nitrogen demand under elevated [CO2] than ambient [CO2], and grain yield had a stronger correlation with plant N uptake after anthesis than before anthesis at high [CO2]. Our results suggest that regulating on the N application rate and time, is likely important for sustainable grain production under future CO2 climate.