Characterisation and application of plant growth under stress of Grass‐planting concrete with alkaline variations

Grass-planting Concrete (GPC) is a slope protection material with excellent flood control and ecological functions. However, its widespread application has been constrained by the high alkalinity and the lack of nutrients of its internal pores. Therefore, investigating the relationship between GPC alkalinity and plant growth characteristics is necessary and meaningful. In this study, trifolium was chosen as a typical grass species, considers GPC alkalinity, soil treatment methods, and nutrient types as influencing factors.It analyzes the changes in GPC alkalinity and soil alkalinity over time and focuses on investigates the growth characteristics and adaptive differences of trifolium before and after root penetrate GPC. Revealing the inhibitory pattern of plant growth by GPC with alkalinity variation. The results showed that (1) GPC significantly inhibited the growth of trifolium , especially before root penetration GPC, where leaf coverage, stem length, root length, root forks and root penetration ability were negatively correlated with alkalinity of GPC. However, after root penetration GPC, the inhibitory effect decreased significantly, especially root length and root forks increased by 3.4 and 4.6 times, respectively. (2) For GPC with surface-covered or internally-filled, the former requires pH < 11 to meet plant growth requirements, while the latter requires a lower pH < 9.(3) On average, trifolium takes 41-63 days to penetrate a 7 cm thick GPC. The lower the initial alkalinity of the GPC, the shorter the time taken for trifolium roots to penetrate, implying greater penetration ability. In addition, filling soil within the GPC can increase root penetration ability.(4) The alkalinity of the GPC has a significant positive correlation with its initial alkalinity and decreases progressively over time. The pH of the soil remains relatively stable, with a slight decrease in the later stages, and is not influenced by the alkaline substances released by the GPC. The growth differences of Trifolium on different GPC • Reducing the alkalinity of GPC helps alleviate the inhibitory effect on trifolium growth. • Surface cover of GPC is more suitable for trifolium growth, while internal fill can enhance root penetration ability. • Before the trifolium penetrates the GPC, its growth is significantly inhibited, with the impact diminishing after penetration. • GPC alkalinity correlates positively with initial levels and declines over time, while soil pH remains stable, unaffected by GPC alkalinity.