Abstract
We use molecular dynamics simulations to investigate the effects of root bending stiffness and packing fraction on the path followed by a growing root in 2D packings of grains representing a soil. The root is modeled as a chain of elements that can grow in length and change their direction depending on the forces exerted by soil grains. We show that the root shape is mainly controlled by the bending stiffness of its apex. At low stiffness, the root randomly explores the pore space whereas at sufficiently high stiffness, of the order of soil hardness multiplied by mean grain size, the root follows a straight path across the soil. Between these two limits, the root shape can be characterized by the standard deviation of its re-directions at the scale of soil grains. We find that this shape parameter varies as a power-law function of the normalized bending stiffness.
Highlights
Besides many other factors such as developmental instability on the cellular level [1], the mechanical interactions between a growing root and its surrounding soil can have major impact on the growth variability and plant biomass production [2,3,4,5,6]
We introduced a model for root growth inside granular materials
This model is characterized by a constant root growth and accounts for the mechanical interactions between the root cap and grains
Summary
Besides many other factors such as developmental instability on the cellular level [1], the mechanical interactions between a growing root and its surrounding soil can have major impact on the growth variability and plant biomass production [2,3,4,5,6]. Continuum representation of soils and roots has been used for describing soil stability [12,13,14,15]. In such models, the effect of soil is incorporated mainly through its average resistance to the root ingrowth and the interactions between soil grains and roots are not considered. There are, on the other hand, functional-structural plant models [16] that describe plant growth and incorporate biological and environmental factors but do not account for the soil strength. Many experiments and observations at the grain scale have shown that grain configuration and local cracks or obstacles have crucial effect on root growth [17,18,19,20,21,22,23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
