Biomechanical properties of the growing and decaying roots of Cynodon dactylon

• Published in: Plant and soil Vol. 471; no. 1-2; pp. 193 - 210
• Main Authors: Kamchoom, Viroon, Boldrin, David, Leung, Anthony Kwan, Sookkrajang, Chanakan, Likitlersuang, Suched
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.02.2022; Springer; Springer Nature B.V
• Subjects: Agricultural land; Agriculture; Analysis; Bermuda grass; Biomechanics; Biomedical and Life Sciences; Burning; Cellulose; Chemical composition; Conversion; Cynodon dactylon; Decay; Diameters; Ecology; Grasses; Growth; herbicide application; Herbicides; land use change; Life Sciences; Lignin; Mechanical properties; Mortality; Plant growth; Plant mechanics; Plant Physiology; Plant Sciences; Reduction; Regular Article; root growth; Roots; Roots (Botany); Slope stability; soil; Soil erosion; Soil Science & Conservation; Soil stability; Tensile strength; weeds; Thailand; United Kingdom; China; Lignin; Root tensile strength; Herbicide; Cellulose; Root decay; Burning
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-021-05207-1

Aim Root growth and decay may affect root reinforcement to soil erosion and stability. We measured the effects of growth and decay on the tensile strength of Cynodon dactylon roots considering different causes of mortality common to agricultural land conversion (i.e. burning and herbicide application). Method We applied three treatments to C. dactylon grass: (i) growth duration (60, 120 and 180 days), (ii) decay duration after burning (30, 60, 120, 180 and 360 days) and (iii) decay duration after herbicide application (15, 30 and 60 days). The diameter, tensile strength and cellulose and lignin contents of root samples (n = 303) in different treatments were measured. Results Tensile strength–diameter relations followed a negative power law regardless of treatment ( R 2  > 0.6). The increase in median tensile strength values due to grass growth was consistent with the increase in cellulose and lignin contents. Root decay by herbicide application caused significantly greater and faster reduction in tensile strength than burning treatment because of the faster reduction of cellulose and lignin contents. Conclusion Root decay due to different causes of plant mortality can increase susceptibility to erosion and slope instability during the conversion of agricultural land. Measures on slope safety and erosion are vital when using herbicides for weed clearance in farmlands due to the faster deterioration of root chemical composition and root tensile strength (compared with burning).