Foliar N/P ratio and nutrient limitation to vegetation growth on Keerqin sandy grassland of North-east China

LI L.-J.; ZENG D.-H.; YU Z.-Y.; FAN Z.-P.; MAO R.; PERI P.L.

GRASS AND FORAGE SCIENCE (PRINT)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2011 vol. 66 p. 237 - 242

0142-5242

To examine whether the critical leaf N⁄ P ratios (of 14, 16) are valid to test nutrient limitation in the context of semi-arid sandy grasslands, an experiment was conducted on a Keerqin sandy grassland in North-east China to investigate the responses of plant biomass and nutrient concentrations to fertilization. Plant biomass production and leaf nutrient concentrations were measured after five consecutive years of fertilization with N (20 g N m-2 year-1) and ⁄ or P (10 g P2O5 m-2 year-1). Nitrogen fertilization increased the shoot biomass by twofold and consequently the shoot ⁄ root ratio, whereas P fertilization had little effect on either shoot biomass or shoot ⁄ root ratio. Leaf N⁄ P ratio varied among species with an average of 5.6 in the control, while the mean leaf N⁄ P ratio (7.5) under the N fertilization treatment remained below the threshold of 14. Our results suggest that the critical N⁄ P ratio (14, 16) is not applicable as a test for nutrient limitations in the context of semi-arid, sandy grassland.