Publications

Journal Article Ahead of print

PubMed: 42708487 DOI: 10.1111/pce.70870

Hydraulic Activation of Stomata Induced by Hygroscopic Fertilizer Salts Alters Crop Carbon-Water Exchange: Field Evidence From Cereal Crops.

Plant Cell Environ

Authors: Shuaishuai Deng, Jürgen Burkhardt, Ronny Lauerwald, Christophe Flechard, Jürgen Knauer, Carmen Kalalian, Benjamin Dumont, Matthias Mauder, Christian Brümmer, Nicolas Viovy, Benjamin Loubet

Affiliations

  • UMR ECOSYS, INRAE AgroParisTech, Université Paris-Saclay, Palaiseau, France.
  • Institute of Crop Science and Resource Conservation, University of Bonn, Bonn, Germany.
  • UMR 1069 SAS, INRAE, Institut Agro, Rennes, France.
  • School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, Australia.
  • ULiege-Gembloux AgroBio-Tech, Plant Sciences Axis, Crop Science Lab. Gembloux, Belgium.
  • Institute of Hydrology and Meteorology, TUD Dresden University of Technology, Tharandt, Germany.
  • Thünen Institute of Climate-Smart Agriculture, Braunschweig, Germany.
  • Laboratoire des Sciences du Climat et de l'Environnement, IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France.

Abstract

Hydraulic activation of stomata (HAS), driven by hygroscopic salt films on leaf surfaces, can create an additional pathway for water loss beyond conventional stomatal vapour diffusion, yet this process remains largely overlooked in studies of plant-atmosphere interactions. We conducted the first field-based assessment of HAS-related responses following foliar interception of hygroscopic urea ammonium nitrate (UAN) fertilizer, using eddy covariance (EC) data from five cropland sites (2005-2021). During the 10-day period following UAN application, vegetation conductance (G veg) increased significantly across barley, winter wheat and maize, while significant increases in the marginal water cost of carbon gain (λ) and stomatal sensitivity (G 1) were observed in barley and winter wheat. This pattern could not be attributed to changes in canopy microclimatic conditions or short-term crop growth, and was not observed with alternative liquid mineral fertilizers. Gross primary productivity (GPP) and inferred transpiration (T) also increased following UAN application, with generally greater responses in T than in GPP in most crop-site combinations. The results suggest that UAN-induced HAS alters crop carbon-water exchange at the ecosystem scale. Neglecting HAS in current models may bias predictions of ecosystem water use in fertilized cereals, with broader implications under widespread hygroscopic aerosol deposition.

MeSH

Plant Physiological Phenomena, Ecosystem, Fertilizers, Plant Cells