%0 Journal Article
%A Konrad, Alexander
%A Billiy, Benjamin
%A Regenbogen, Philipp
%A Bol, Roland
%A Lang, Friederike
%A Klumpp, Erwin
%A Siemens, Jan
%T Forest Soil Colloids Enhance Delivery of Phosphorus Into a Diffusive Gradient in Thin Films (DGT) Sink
%J Frontiers in forests and global change
%V 3
%@ 2624-893X
%C Lausanne
%I Frontiers Media
%M FZJ-2021-01014
%P 577364
%D 2021
%X Phosphorus (P) is preferentially bound to colloids in soil. On the one hand, colloids may facilitate soil P leaching leading to a decrease of plant available P, but on the other hand they can carry P to plant roots, thus supporting the P uptake of plants. We tested the magnitude and the kinetics of P delivery by colloids into a P sink mimicking plant roots using the Diffusive Gradients in Thin-Films (DGT) technique. Colloids were extracted with water from three forest soils differing in parent material using a method based on dispersion and sedimentation. Freeze-dried colloids, the respective bulk soil, and the colloid-free extraction residue were sterilized and mixed with quartz sand and silt to an equal P basis. The mixtures were wetted and the diffusive fluxes of P into the DGTs were measured under sterile, water unsaturated conditions. The colloids extracted from a P-poor sandy podzolic soil were highly enriched in iron and organic matter compared to the bulk soil and delivered more P at a higher rate into the sink compared to bulk soil and the colloid-free soil extraction residue. However, colloidal P delivery into the sink was smaller than P release and transport from the bulk soil developed on dolomite rock, and with no difference for a soil with intermediate phosphorus-stocks developed from gneiss. Our results provide evidence that both the mobility of colloids and their P binding strength control their contribution to the plant available P-pool of soils. Overall, our findings highlight the relevance of colloids for P delivery to plant roots.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000614091500001
%R 10.3389/ffgc.2020.577364
%U https://juser.fz-juelich.de/record/890527