Root exudates affecting P phytoavailability in soils - biogeochemical mechanisms and experimental approaches

Wien

2014

S. 13

Artikel aus einer ZeitschriftUnselbständiges Werk

200189773

Roots release a range of organic as well as inorganic molecules of which some (particularly organic acids) have been implicated to play an important role in increasing plant P nutrition. Accurate sampling and determination of release rates of root exudates is a prerequisite for further mechanistic investigations that will lead to a better understanding of the processes and dynamics involved in P mobilisation. Different experimental approaches (soil vs hydroponic culture) to sample root exudates will be presented and compared, including a new, rhizobox-based approach that enables us to repeatedly collect unaltered root exudates from soil grownplants. Implications of the differences in results obtained by the different experimental approaches will be discussed. Furthermore we aim to summarize the biogeochemical mechanisms that can be triggered by roots to increase P solubility, with particular focus on the effectiveness of various root exudate compounds in contrasting soil types with differing P amounts and chemistries. Supported by experimental data we will demonstrate that depending on soil properties plants should ideally pursue different strategies to improve P phytoavailability in the rhizosphere.