A trade-off between nitrogen uptake and use increases responsiveness to elevated CO2 in infrequently cut mixed C3 grasses
Article first published online: 8 FEB 2005
Volume 166, Issue 1, pages 217–230, April 2005
How to Cite
Soussana, J.-F., Teyssonneyre, F., Picon-Cochard, C. and Dawson, L. (2005), A trade-off between nitrogen uptake and use increases responsiveness to elevated CO2 in infrequently cut mixed C3 grasses. New Phytologist, 166: 217–230. doi: 10.1111/j.1469-8137.2005.01332.x
- Issue published online: 8 FEB 2005
- Article first published online: 8 FEB 2005
- Received: 30 July 2004 Accepted: 28 October 2004
- carbon dioxide (CO2);
- climate change;
- N cycle;
- nitrogen-use efficiency;
- N productivity;
- • The aim of this study was to evaluate whether the responsiveness of mixed C3 grass species to elevated CO2 is related more to nitrogen uptake or to N-use efficiency.
- • Nitrogen uptake and whole-plant N-use efficiency were investigated with two binary mixtures: Lolium perenne was mixed either with Festuca arundinacea or with Holcus lanatus. The swards were grown on sand with or without CO2 doubling, and subjected to two cutting frequencies. A C20 alcohol was used as a marker to determine species proportion in the total root mass of the mixtures. The mean residence time of N was calculated from that of 15N-labelled fertilizer.
- • Lolium perenne took up significantly more N per unit root mass than its grass competitors, but its N-use efficiency was lower. Elevated CO2 significantly reduced the N uptake of the three grass species.
- • A trade-off between N capture and use was found, as N-use efficiency and N-uptake rate were negatively correlated. A high N-use efficiency, and conversely low N uptake appeared to favour the responsiveness to elevated CO2 of the infrequently cut grasses.