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Effects of aerobic conditions in the rhizosphere of rice on the dynamics and availability of phosphorus in a flooded soil – A model experiment
Author(s) -
Zhang Yongsong,
Lin Xianyong,
Werner Wilfried
Publication year - 2004
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.200320349
Subject(s) - rhizosphere , chemistry , desorption , phosphorus , adsorption , anaerobic exercise , sorption , agronomy , bulk soil , soil water , environmental chemistry , soil science , soil organic matter , environmental science , biology , physiology , genetics , organic chemistry , bacteria
Abstract The secretion of O 2 by rice roots results in aerobic conditions in the rhizoshere compared to the bulk flooded soil. The effect of this phenomenon on the adsorption/desorption behavior and on the availability of phosphorus (P) in a flooded soil was investigated in a model experiment. An experimental set‐up was developed that imitates both O 2 release and P uptake by the rice root. The results showed that O 2 secretion significantly reduced P adsorption/retention and increased P desorption/release in the “rhizosphere” soil, compared to the anaerobic bulk soil. The P uptake by an anion exchange resin from both unfertilized and P‐amended soil was significantly increased. The results confirm that the O 2 secretion is an important mechanism to enhance P availability and P uptake of rice under flooded conditions, where the “physico‐chemical” availability of P in the anaerobic bulk soil is strongly reduced. The decrease of P availability in the P‐amended flooded bulk soil was mainly associated with the almost complete transformation of the precedingly enriched Al‐P fraction into Fe‐bound P with extremely low desorption/release characteristics during the subsequent flooding.