Connecting soil spatial heterogeneities and grapevine root system architecture in California’s Central Valley using non-invasive geophysical methods

Authors: EHOSIOKE, SOLOMON - University Of California, Davis; DUDLEY, SAM - University Of California, Davis; McElrone, Andrew; BARTLETT, MEGAN - University Of California, Davis; Osterman, Gordon

Submitted to: Rhizosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2025
Publication Date: 12/12/2025
Citation: Ehosioke, S., Dudley, S., McElrone, A.J., Bartlett, M., Osterman, G.K. 2025. Connecting soil spatial heterogeneities and grapevine root system architecture in California’s Central Valley using non-invasive geophysical methods. Rhizosphere. 37. Article 101247. https://doi.org/10.1016/j.rhisph.2025.101247.
DOI: https://doi.org/10.1016/j.rhisph.2025.101247

Interpretive Summary: Variations in soil types across vineyards can impact grapevine performance and water use efficiency, but the subsurface mechanisms that control this are poorly understood. Here, we use a mix of direct coring and non-invasive geoelectrical measurements to study grapevine physiology and root morphology to investigate how soil impacts these characteristics for grapevines in California's Central Valley. Specifically, we employed electromagnetic induction and electrical resistivity tomography to map the soil variability, and multi-frequency capacitance measurements on individual vines. Then, we extracted soil and root cores from the same vines to directly measure the root system size. We found that the capacitance measurements effectively correlate with root length, with the correlation varying between types of grapevine, while the soil mapping revealed how differences in soil properties can influence the bio-geoelectrical properties across the vineyard. These findings highlight the potential of "agro-geophysics" for to improve site-specific vineyard management, allowing practitioners to optimize irrigation strategies, and aid in rootstock selection for enhanced drought resilience.

Technical Abstract: Soil spatial heterogeneity significantly impacts grapevine performance and water-use efficiency, yet understanding the intricate belowground dynamics remains a challenge. This study integrates non-invasive geophysical methods with physiological measurements and root morphology analysis to investigate the influence of soil variability on two grapevine rootstocks, Millardet et de Grasset 101-14 (101-14 Mgt) and Richter 110 (110R), in California's Central Valley. Electromagnetic induction and electrical resistivity tomography were used to map soil spatial heterogeneity, revealing distinct soil units (Yolo silt loam and Reiff very fine sandy loam) with varying physical and hydraulic properties. Electrical capacitance measurement successfully evaluated root system size as we found a positive correlation between root electrical capacitance and root dry mass in both rootstocks. Our results also show that root capacitance was consistently higher in the high vigor and drought resistant 110R than in the moderate vigor and drought sensitive 101-14, highlighting root system differences between the rootstocks. Furthermore, we found that vine water status, indicated by stem water potential and stomatal conductance, varied significantly between rootstocks and locations, and are driven by the underlying soil properties. This research demonstrates the utility of integrating geophysical and electrical methods for field-based phenotyping, providing novel insights into the soil-plant continuum. These findings highlight the potential of agrogeophysics for characterizing vineyard spatial heterogeneity to inform site-specific vineyard management, optimize irrigation strategies, and aid in rootstock selection for enhanced drought resilience without the need for labor intensive excavations.