Root-system development and water-extraction model considering hydrotropism

• Published in: Soil Science Society of America journal Vol. 67; no. 2; pp. 387 - 401
• Main Authors: TSUTSUMI, D, KOSUGI, K, MIZUYAMA, T
• Format: Journal Article
• Language: English
• Published: Madison, WI Soil Science Society of America 01.03.2003; American Society of Agronomy
• Subjects: Biological and medical sciences; Evaporation; Fundamental and applied biological sciences. Psychology; Irrigation water; Moisture content; Plant growth; Roots; Soil water; Soils; Water flow; Water resources
• ISSN: 0361-5995; 1435-0661; 1435-0661
• DOI: 10.2136/sssaj2003.0387

A two-dimensional model that combines root-system development and water extraction by roots is proposed to simulate the dynamic interaction between root growth and soil-water flow. Both of hydrotropism and gravitropism were considered as the controlling factors of root growth in the proposed root-system development model. The finite-element method was employed to compute the soil-water flow caused by water extraction, evaporation, and irrigation. We succeeded in simulating the plagiogravitropic elongations of lateral roots under a plane condition, and the asymmetric architecture of root system under a slope condition by the proposed model in which the root hydrotropism is considered. On the other hand, we cannot simulate such morphological characteristics of a root system by the use of the conventional model in which a random elongation factor is employed, and root hydrotropism is not considered. The results support the importance of hydrotropism in root-system development and the availability of the proposed model in which the hydrotropism is considered.