ENHANCING GROWTH, SOIL CHEMISTRY, AND NUTRIENT UPTAKE IN SONNERATIA CASEOLARIS SEEDLINGS UNDER SALINITY STRESS THROUGH BIOCHAR APPLICATION

Mangrove forests are well-known for their capability to withstand strong tides and play a crucial role in the aquatic ecosystem. However, anthropogenic factors combined with natural stressors have high chances of affecting the nutrient content, increased salinity and anoxic environment of mangroves, which influences their growth performances. Sonneratia caseolaris is a mangrove plant that resides in areas with fresh water due to its weak resistance against high saline waters. A six-months study was conducted to evaluate if biochar application alleviated salinity stress via modifying sediment properties and nutrient uptake of Sonneratia caseolaris seedlings. Five treatments were evaluated in this study: control; mangrove soil without biochar application (T1), 10% of B. parviflora biochar (T2), 20% of B. parviflora biochar (T3), 10% of G. levis biochar (T4), and 20% of G. levis biochar (T5). From the study, treatment 3 (20% B. parviflora biochar) proved the best improved growth performance which gave the highest plant height, stem diameter, biomass dry weight, root fresh weight, length of entire plant, length of primary root, and signifies a good impact for the growth of seedlings. In addition, application of biochar generally increase the exchangeable cations: K, Mg and Ca in sediment and the total P, K and Mg content in plant compared to control. This demonstrated the potential of the treatment as a soil amendment to not only improved soil properties, but also enhancing Sonneratia caseolaris plants’ tolerance towards salinity stress. Hence, B. parviflora biochar proved as the best quality of biochar and can improve the growth of mangrove plant seedlings including root growth and development as well sediment chemical properties and nutrient uptake.