INVESTIGADORES
RUBIO Gerardo
artículos
Título:
Seasonally-dependent response to soil nutrient enrichment in C3 and C4 grasses
Autor/es:
RUBIO G, GUTIERREZ BOEM F.H. AND LAVADO
Revista:
GRASS AND FORAGE SCIENCE (PRINT)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2010 vol. 65 p. 102 - 109
ISSN:
0142-5242
Resumen:
In grasslands composed by C3 and C4 plants, a different pattern of response to fertilization may lead to a change in the floristic composition of the community. Our objective was to evaluate the combined effects of N and P additions and temperature on the aerial growth of C3 and C4 grasses. Danthonia montevidensis and Stipa neesiana (C3), and Setaria geniculata and Sporobolus indicus (C4), were selected from a native grassland of the Flooding Pampa, Argentina. We run two consecutive experiments (early and late spring) in pots filled with the local soil. Whereas C3 grasses showed no responses to P or N in most studied growth parameters, their C4 counterparts showed a consistent response. The season factor (temperature and maybe irradiance), rather than nutrients, appeared to be the main limiting factor of C3 species. The response to fertilization in C4 plants showed a high season-dependence: we found an average of 1.8 and 2.5 fold biomass increase in early and  late spring, respectively. The fact that only C4 plants responded positively to P and N indicates that the differences between metabolic types were not related to a particular nutrient but to a higher demand to sustain greater growth rates.