, Volume 294, Issue 1-2, pp 137-146

Responses of rice and winter wheat to free-air CO2 enrichment (China FACE) at rice/wheat rotation system

Purchase on Springer.com

$39.95 / €34.95 / £29.95*

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Free-air CO2 enrichment (FACE) system at a Chinese rice–wheat rotation field was constructed to investigate responses of rice and wheat crop growth to elevated CO2 and nitrogen fertilization. A factorial experiment design was set up with two levels of atmospheric CO2 concentration (350 and 550 μmol mol−1) and N application rates (LN: 150 kg N ha−1 for rice and 125 kg N ha−1 for wheat; HN: 250 kg N ha−1 for rice and wheat, respectively). Across the entire crop growing seasons, plant fractions (i.e. leaf, stem, ear and root) were differentiated at representative growth stages and analyzed using widely recognized parameters, relative growth rate (RGR) and allometric coefficient K a (RGR ratio of above ground to below ground plant biomass). The C/N ratio and phosphorus concentration of plant were also determined. Rice and wheat RGRs responded to elevated CO2 in different ways, i.e. wheat RGR was always stimulated by elevated CO2 while rice RGR seemed to be depressed between rice tillering to jointing stages. Elevated CO2 affected the plant fractions differentially. For example, rice leaf might be the most strongly affected organ by RGR analysis and by K a analysis it seems that elevated CO2 always led to higher below ground biomass (root) than above ground biomass. Besides, elevated CO2 usually resulted in a higher C/N ratio of plant due to its impact on N concentration instead of carbon. Regardless of CO2 treatment statistic analysis of rice and wheat RGR did not yield significant difference in plant growing patterns under LN and HN treatments, although LN always triggered a slightly higher C/N ratio of plant over the investigated period. Furthermore, it was generally observed that elevated CO2 could stimulate crop biomass to a greater extent under LN treatment than HN treatment. Phosphorus concentration of rice and wheat crop showed distinctive response to elevated CO2 and N constraint.