Plant-soil water relationships in hillslope vineyards – A time-lapse ERT 3d monitoring

Abstract

Viticulture is often practiced on slopes, and water dynamics in these situations are generally more complex than in valley or in plains. In order to gain further insight into this phenomena, 8 plots of grapevine were monitored during 2012 vintage on the Corton Hill slope, Burgundy, France. They were distributed along a toposequence from 330 to 270 meters a.s.l. Grapevines were weekly monitored by surveying their water potential. Soil volumetric humidity was measured using a TDR probe with 3 tubes installed in each plots up to 2 m depth for deepest soils. Time-Lapse Electrical Resistivity Tomography (ERT) 2D was used weekly for monitoring variations in the electrical resistivity of soil. During 2012, in Burgundy, grapevines experienced a large variation in hydric status, which ranged from low to considerable water deficit (as expressed by predawn leaf water potential). ERT and TDR measurements showed the same pattern and were significantly correlated in function of soil texture and the amount of gravels present. This relationship allowed to use ERT as a proxy to spatialise volumetric water content in 2D. Volumetric water content (VWC) significantly differentiated the plots during the season. In addition, VWC and ERT measurement were significantly related to grapevine physiology. The significant relationships observed between electrical resistivity and leaf water potential suggest that in the future using electrical resistivity might be adopted as a proxy for the spatialisation of plant water stress in the field.