Purpose <p>The aging of <i>Casuarina equisetifolia (C. equisetifolia)</i> in coastal shelterbelts and the depletion of soil nutrients has led to a decline in their protective capabilities, with significant differences among various soil types. This study investigates the effects of soil nutrient availability on the growth mechanisms of <i>C. equisetifolia</i> shelterbelts in red soil and sandy soil regions, aiming to offer guidance for the establishment and functional improvement of coastal shelterbelt systems.</p> Methods <p>Shelterbelts of <i>C. equisetifolia</i> at different growth stages were selected for analysis using ANOVA, Pearson correlation analysis, stepwise regression, and redundancy analysis (RDA) to elucidate the relationship between soil nutrients and the growth of <i>C. equisetifolia</i> stands.</p> Results <p>Stand age and soil type had significant effects on soil nutrient status, as total potassium (TK) and available potassium (AK) exhibited divergent trends depending on soil type. Soil nutrients were closely associated with growth indicators of <i>C. equisetifolia</i>, and phosphorus consistently exerted a significant influence on growth in both soil types. However, the effects of soil pH, total nitrogen (TN), TK, and organic matter (OM) varied by soil type. RDA results further indicated that soil nutrients explained 88.5% of the variation in stand parameters in the red soil region and 62.5% in the sandy soil region.</p> Conclusion <p>Soil type and nutrient content had significant impacts on the growth conditions of <i>C. equisetifolia</i> shelterbelts. Soil-type-specific management strategies are recommended to enhance the ecological stability and protective functions of coastal shelterbelt systems.</p>