Plant nitrogen and phosphorus limitation in 98 North American grassland soils

TitlePlant nitrogen and phosphorus limitation in 98 North American grassland soils
Publication TypeJournal Article
Year of Publication2009
AuthorsCraine JMitchell, Jackson RD
JournalPlant and Soil
VolumeOnline DOI 10.1007/s11104-009-0237-1
Paginationpp 1-12
Date Published2009
ISBN Number0032-079X
Call Number00968
Keywordsarticle, biomass, grassland, colimitation, grass, Schizachyrium scoparium, grassland, journal, nitrogen, phosphorus, soil nitrogen, soil nutrients, nitrogen, soil nutrients, phosphorous, stoichiometry
AbstractThe availability of nutrients is a critical determinant of ecological dynamics in grasslands, but the relationships between soil resource availability and nutrient limitation across ecosystems are not clear. To better understand how soil nutrient availability determines nutrient limitation in vegetation, we grew the same species of grass (Schizachyrium scoparium) in 98 North American grassland soils and fertilized them factorially with nitrogen (N) and phosphorus (P). On average adding N, P, and the two nutrients together increased biomass relative to unfertilized plants by 81%, 22%, and 131%, respectively. Plants grown on low-P soils were not primarily limited by P. Instead, these plants were colimited by N and P, while plants grown on high-P soils were primarily limited by N and only secondarily limited by P. Limitation was not predicted by total soil N. The preponderance of colimitation between N and P on low-P soils suggests that low P availability alters the N cycle to constrain supplies to plants such that N and P are made available in proportion to their demand by plants.
Reprint Edition (12/11/2009)