Plant and Soil

, Volume 342, Issue 1, pp 249–263

Phytotoxicity of glyphosate soil residues re-mobilised by phosphate fertilisation

Authors

    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Tsehaye Tesfamariam
    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Angelika Kania
    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Birceyudum Eman
    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Nergiz Aslan
    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Volker Römheld
    • Institut für Pflanzenernährung (330)Universität Hohenheim
  • Günter Neumann
    • Institut für Pflanzenernährung (330)Universität Hohenheim
Regular Article

DOI: 10.1007/s11104-010-0689-3

Cite this article as:
Bott, S., Tesfamariam, T., Kania, A. et al. Plant Soil (2011) 342: 249. doi:10.1007/s11104-010-0689-3

Abstract

It has been repeatedly demonstrated that phosphate (P) and the herbicide glyphosate compete for adsorption sites in soils. Surprisingly, the potential consequences of these interactions for plants e.g. re-solubilisation of phytotoxic glyphosate residues in soils by application of P fertilisers or by root-induced mechanisms for P mobilization have not been investigated so far. In model experiments under greenhouse conditions, the potential for glyphosate re-mobilisation by P-fertiliser application was evaluated by bio-indication with soybean (Glycine max L.) cultivated on five contrasting soils with or without glyphosate application at 10–35 days before sowing. Different levels of P-fertilisation (0, 20, 40, 80, 240 mg P kg−1 soil) were supplied at the date of sowing. Visual symptoms of glyphosate toxicity, plant biomass, intracellular shikimate accumulation as physiological indicator for glyphosate toxicity and the plant nutritional status were determined. On glyphosate-treated soils, P application induced significant plant damage. Expression of damage symptoms declined in the order Arenosol > Acrisol ≈ Ferralsol > Luvisol subsoil > Regosol. On the Arenosol, Ferralsol and Luvisol subsoil plant damage was associated with increased shikimate accumulation in the root tissue. On the Acrisol decline of germination and plant damage in absence of shikimate accumulation indicate toxicity of AMPA (aminomethylphosphonic acid) as the main metabolite of glyphosate in soils. On the Regosol, a growth-stimulating effect of glyphosate soil application (hormesis) was detected. The results suggest that re-mobilisation of glyphosate may represent an additional transfer pathway for glyphosate to non-target plants which is strongly influenced by soil characteristics such as P fixation potential, content of plant-available iron, pH, cation exchange capacity, sand content and soil organic matter.

Keywords

Glyphosate Phosphorus Re-mobilisation Rhizosphere Root growth Micronutrients

Abbreviations

a.e.

acid equivalent

AMPA

aminomethylphosphonic acid

cv.

cultivar

DAS

days after sowing

n.d.

not determined

N.S.

not significant

SOM

soil organic matter

WHC

water holding capacity

Copyright information

© Springer Science+Business Media B.V. 2011