caa a22 4500 606218432 CHVBK 20210128101112.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s11104-014-2275-6 doi (NATIONALLICENCE)springer-10.1007/s11104-014-2275-6 Impact of potassium on plant uptake of non-exchangeable NH4 +-N [Elektronische Daten] [Patrick Beuters, Heinrich Scherer, Oliver Spott, Doris Vetterlein] Aims and background: Release of ‘non-exchangeable' NH4 +-N from interlayers of 2:1 clay minerals is postulated to depend not only on soil solution NH4 +-N concentration but also on the concentration of K+ and Ca2+. Concentrations of all three cations are altered in rhizosphere compared to soil solution at larger distance from the root surface. Methods: Non-exchangeable NH4 +-N pool was labelled with 15 N. Treatments including application of K+, Ca2+ and K+ + Ca2+ were established. In a compartment system approach we analysed changes in soil solution concentrations of 15NH4 +-N, 15NO3 −-N, K+ and Ca2+ in situ at different distances from the root surface over time and related them to the release of non-exchangeable 15NH4 +-N and uptake of 15 N by plants. Results and conclusions: The 15 N enrichment in plant tissue was significantly lower in treatments with K+ application compared to those without. This was in line with smaller depletion of non-exchangeable 15NH4 +-N in the rhizosphere for these treatments and also with lower 15 N abundance in soil solution NO3 −-N fraction. Hence, K+ application hampered the release of NH4 + from the interlayers. A promoting effect of increasing Ca2+ concentrations on release of non-exchangeable NH4 +-N could not be evaluated since the Ca2+ concentration in soil solution was largely controlled by small amounts of carbonate contained in the substrate and thus the addition of Ca2+ did not result in a relevant increase of soil solution Ca2+ concentration as originally intended. The use of 15 N to follow the fate of non-exchangeable NH4 +-N proved very useful as it provides a higher sensitivity for all measured fractions compared to total N. However, as soil N fractions equilibrate with each other labelling one fraction exclusively is not possible. Springer International Publishing Switzerland, 2014 Clay minerals nationallicence Non-exchangeable NH4 +-N nationallicence Rhizosphere nationallicence Soil solution nationallicence Stable isotopes nationallicence Beuters Patrick Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany aut Scherer Heinrich Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany aut Spott Oliver Department of Soil Physics, Helmholtz Centre for Environmental Research - UFZ, Theodor-Lieser-Str. 4, 06120, Halle/Saale, Germany aut Vetterlein Doris Department of Soil Physics, Helmholtz Centre for Environmental Research - UFZ, Theodor-Lieser-Str. 4, 06120, Halle/Saale, Germany aut Plant and Soil Springer International Publishing 387/1-2(2015-02-01), 37-47 0032-079X 387:1-2<37 2015 387 11104 https://doi.org/10.1007/s11104-014-2275-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-014-2275-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Beuters Patrick Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany aut NATIONALLICENCE 700 1- Scherer Heinrich Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Straße 13, 53115, Bonn, Germany aut NATIONALLICENCE 700 1- Spott Oliver Department of Soil Physics, Helmholtz Centre for Environmental Research - UFZ, Theodor-Lieser-Str. 4, 06120, Halle/Saale, Germany aut NATIONALLICENCE 700 1- Vetterlein Doris Department of Soil Physics, Helmholtz Centre for Environmental Research - UFZ, Theodor-Lieser-Str. 4, 06120, Halle/Saale, Germany aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 387/1-2(2015-02-01), 37-47 0032-079X 387:1-2<37 2015 387 11104