Plant root penetration and growth as a mechanical inclusion problem

• Published in: International journal of non-linear mechanics 2020-04, Vol.120, p.103344, Article 103344
• Main Authors: Calusi, B., Tramacere, F., Gualtieri, S., Pugno, N.M., Mazzolai, B.
• Format: Article
• Language: English
• Subjects: Elasticity; Elongation; Evolution; Growth model; Mechanical inclusion; Penetration; Plant roots; Root penetration; Soil dynamics; Soil mechanics; Soils; Stimuli
• ISSN: 0020-7462; 1878-5638
• DOI: 10.1016/j.ijnonlinmec.2019.103344

The ability of plant roots to penetrate soils is affected by several stimuli exerted by the surrounding medium, such as mechanical stresses and chemical stimuli. Roots have developed different adaptive responses, such as increase or decrease of the elongation rate of the apical region and swelling or shrinking of its diameter. We propose a mathematical model aimed at explaining the dynamic evolution of plant roots during the penetration into the soil. We treat the root as a cylinder and the root–soil interaction as a purely mechanical inclusion problem. In particular, the root dynamic evolution is based on a modified version by one of the authors of the extended universal law of West, Brown, and Enquist. Coupling the solution of the mechanical problem and the growth equation, we compare the theoretical results with experimental data collected in artificial and real soils. In this work, we propose a plausible interpretation of the experimental results of the root behavior during the growth inside the surrounding soil medium. •This work proposes a mathematical model of the plant root growth into soil media.•The root–soil mechanical interaction is considered as a mechanical inclusion model.•Mechanical properties of the soil medium might alter the root behavior.