Remobilized old-leaf nitrogen predominates for spring growth in two temperate grasses
Article first published online: 21 DEC 2001
Volume 152, Issue 2, pages 283–290, November 2001
How to Cite
Bausenwein, U., Millard, P. and Raven, J. A. (2001), Remobilized old-leaf nitrogen predominates for spring growth in two temperate grasses. New Phytologist, 152: 283–290. doi: 10.1046/j.0028-646X.2001.00262.x
- Issue published online: 21 DEC 2001
- Article first published online: 21 DEC 2001
- Received: 9 March 2001 Accepted: 17 July 2001
- Festuca rubra;
- Agrostis capillaris;
- perennial grass;
- nitrogen remobilization;
- nitrogen translocation;
- internal cycling;
- seasonal growth;
- spring growth
- • The importance of N derived from internal remobilization and root uptake to growth in spring is reported here for the perennial grasses Festuca rubra and Agrostis capillaris derived from seminatural grasslands in Scotland, UK.
- • Plants grown in sand culture, received 15N-enriched nutrient solution during the first year of growth and nutrient solution with N at natural abundance during the subsequent spring and summer when destructive harvests were taken.
- • Labelled N was recovered in new growth of overwintering tillers and new tillers. Remobilized N contributed 70% and 82% for F. rubra and A. capillaris, respectively, to the total N in new above-ground growth in early spring, declining to 34% and 45%, respectively, by mid June. Species showed similar patterns of remobilization on a new growth biomass basis. The root system did not remobilize N to support new above-ground growth. Labelled N was derived from senescing leaves present on overwintering tillers. Net balances of labelled N suggest that N was translocated between tillers; reproductive tillers acted as sinks, vegetative tillers as the source of N.
- • Initial growth in spring is largely independent of N uptake from the soil, provided that overwintering leaves are present on the plants.