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Rhizosphere phosphorus depletion by three crops differing in their phosphorus critical levels
Author(s) -
Rubio Gerardo,
Faggioli Valeria,
Scheiner Javier D.,
GutiérrezBoem Flavio H.
Publication year - 2012
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.201200307
Subject(s) - rhizosphere , sunflower , helianthus annuus , phosphorus , agronomy , nutrient , soil water , bulk soil , chemistry , fractionation , helianthus , biology , ecology , bacteria , genetics , organic chemistry
It has been reported for many soils that maize ( Zea mays L.) has a higher soil‐P critical level than soybean ( Glycine max L.) and sunflower ( Helianthus annuus L). The objective of this work was to compare the rhizosphere P depletion in these three species in order to investigate if they differ in their capacity to acquire soil P. Sequential P fractionation and pH were determined in rhizosphere and nonrhizosphere soil samples from field and greenhouse experiments. Neither sunflower (the species with highest rhizosphere acidification) nor soybean or maize showed a significant relationship between P depletion and rhizosphere pH. The labile P fraction and the NaOH‐P i fraction had lower values in the rhizosphere than in the bulk soil in 38% and 77% of the studied cases, respectively. Sunflower and especially maize presented a more intense P i depletion than soybean. The comparison between sunflower and maize revealed that neither of them took a clear advantage over the other in terms of P depletion. Rhizosphere P i depletion was associated with the amount of P acquired by the plants. We conclude that the accessibility to different P pools does not explain the differences in soil‐P critical levels among the three species.