Biochar-enhanced biostimulation of maize under salinity stress: a sustainable approach to physiological recovery and soil resilience

Salinity is a major abiotic stress limiting maize (Zea mays L.) productivity, particularly in arid and semi-arid regions. This study evaluated the efficacy of gibberellic acid (GA3) and biochar in mitigating salinity-induced growth inhibition in maize. The objective was to assess the synergistic effects of GA3 and biochar on germination, growth parameters, and photosynthetic capacity under saline conditions, and to identify practical strategies for improving crop performance in salt-affected soils. A pot experiment was conducted at the Islamia University of Bahawalpur, Pakistan, using a Completely Randomized Design (CRD) with four replications per treatment, resulting in 32 pots. The study included eight treatment combinations: control, GA3, biochar, and GA3 + biochar under two salinity levels (2.41 and 6 dSm(-)1). Key parameters analyzed included germination rate, shoot and root length, shoot and root biomass, protein content, and chlorophyll content. Under high salinity (6 dSm(-)1), the combined application of GA3 and biochar improved germination to 73.5% +/- 0.5 compared to 66.5% +/- 0.5 in the control. Shoot and root lengths increased to 16.28 +/- 0.15 cm and 5.90 +/- 0.12 cm, respectively, compared to 10.73 +/- 0.45 cm and 5.16 +/- 0.05 cm in the control. Chlorophyll content also increased, indicating improved photosynthetic performance. The findings demonstrate that GA3 and biochar together can alleviate the adverse effects of salinity stress by promoting early growth and physiological performance in maize. Incorporating these amendments into agronomic practices may provide a sustainable strategy to enhance maize productivity in saline soils. Future studies should evaluate their long-term effects on soil health, nutrient dynamics, and crop yield under field conditions.