A bioenergetic model of plant root growth in soil

Abstract

Crop simulation models commonly require predictive or experimental information on root growth and the distribution of roots in soil. This model calculates the elongation rate of a single root under the influence of internal biophysical and metabolic processes, and external soil physical constraints. The model is derived from consideration of energy conservation in growing root tissue. The derivation starts with a statement of the change in component thermodynamic potentials that perform the work of root growth. The result is a simplified, algebraic statement for root elongation rate as a function of tissue osmotic potential, turgor, soil water potential, mechanical impedance, biosynthetic heat production, tissue plasticity and meristematic cell production. Simulated results are in qualitative agreement with current knowledge and concepts of plant root growth in soil. The model should thus form the basis of a simplified, mechanistic tool for describing plant root growth suitable for use in crop simulation models.