Biochar as a drought mitigation tool to enhance growth and water retention in <em>Pinus caribaea</em> M. seedlings

Drought stress significantly challenges tree growth, especially in tropical forestry systems. This study investigates the effect of biochar amendments and different watering regimes on the physiological responses of Pinus caribaea seedlings to drought stress. The experiment was conducted in a controlled nursery environment using three biochar concentrations (0%, 3%, and 6%) and three watering intervals (100 mL every 24, 48, and 96 hours). A total of 300 seedlings were monitored for growth parameters, including height and diameter. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to assess treatment effects. Results demonstrated that higher biochar levels significantly improved growth metrics and water retention. The 6% biochar treatment yielded the greatest increases both in diameter and height, with enhanced water retention attributed to biochar’s ability to improve soil structure and nutrient retention. Moreover, frequent watering in combination with biochar amendments further boosted seedling growth. PCA revealed negative correlations between drought intensity and growth, while biochar treatments correlated positively with improved growth. The findings suggest that biochar amendments can effectively mitigate drought stress in Pinus caribaea seedlings, promoting improved growth and water conservation.