Enhancement of plant growth and soil stabilization by seaweed polysaccharides in the red soil region of Southern China
Year: 2026
Type: article
Abstract: Red soil is the second most extensively eroded soil type in China, predominantly distributed in the southern regions. Vegetative measures are widely recognized as an effective approach for controlling soil erosion in red soil areas, as they enhance slope stability and substantially reduce soil loss. However, during the early growth stages, the short and fine roots of plants are unable to extend beyond the shear failure surface, which constrains their capacity to stabilize the surface soil. To address this limitation, researchers have introduced seaweed polysaccharides as a soil ameliorant. Nevertheless, the specific mechanisms by which seaweed polysaccharides influence plant growth, root-soil complex mechanics, and the erosion resistance of red soil remain poorly understood. Accordingly, an experimental study was conducted to investigate the enhancement of plant growth and soil stabilization by seaweed polysaccharides in red soil. The results indicate that (1) seaweed polysaccharides exhibited an optimal concentration range for improving red soil. At concentrations below 2%, seed germination, plant height, and stem growth were promoted, whereas concentrations exceeding 2% exerted inhibitory effects. (2) In terms of mechanical properties, seaweed polysaccharides significantly enhanced the shear strength of the soil. Compared with the control group, application of seaweed polysaccharides increased the cohesion and internal friction angle by 103.68% ~ 180.52% and 13.92% ~ 31.76%, respectively. When seaweed polysaccharides acted in conjunction with plant roots, the improvement was further amplified, with increases of 143.33% ~ 220.65% in cohesion and 14.83% ~ 39.45% in the internal friction angle. (3) Under simulated rainfall conditions, the sediment yield from the slope significantly decreased with increasing seaweed polysaccharide addition. The synergistic effect of seaweed polysaccharides and plant roots arises from the formation of a “seaweed polysaccharide-red soil-root” three-phase unit structure, in which the polysaccharides encapsulate and connect roots with soil particles, thereby enhancing the integrity and flexibility of the root-soil complex. These findings not only broaden the selection of soil reinforcement materials but also provide theoretical guidance for vegetation restoration and soil and water conservation in red soil regions.
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
SDGs: Life on land, Zero hunger
Open Access status: gold
Estimated APC paid: $3,077
OpenAlex ID: W7223352185