Soil organic N supply from the perspective of a root - a microdialysis approach

Wien

2014

Artikel aus einer ZeitschriftUnselbständiges Werk

17215

200189732

The availability of nitrogen (N) for root uptake largely regulates plant biomass production in terrestrial ecosystems and directly influences plant-soil interactions. Detailed knowledge about the concentration and composition of soil N pools are therefore crucial for studying and understanding plant N nutrition. Until now this remained a challenging task, due to the disruptive nature of current sampling techniques, further implying that results from destructive soil sampling are only poor indicators for in situ soil N concentrations. Further, plant N acquisition is determined by the flux of N from the surrounding soil to root surfaces rather than by soil N concentrations. Recently, a non-invasive sampling technique based on passive microdialysis was presented as a possible tool to estimate concentrations and fluxes of N in soils in-situ. Unlike other sampling methods the miniaturized design and the passive sampling approach allows for continuous monitoring of soil N fluxes at an unrivalled spatial and temporal resolution. Further, microdialysis has the potential to study N dynamics in soil microsites and to simulate the formation of depletion zones around the microdialysis probes, similar to zones in the rhizosphere. I discuss advantages and disadvantages of microdialysis for studying plant-available N compared to other sampling techniques.