impact of salicylic acid seed priming on germination and the combined effect of biochar and salicylic acid on plant nutrient content under salt stress

In the initial phase of this study, the germination traits of maize seeds subjected to salicylic acid (sa) priming under saline stress were investigated. the treatments consisted of five sa concentrations: 0 (distilled water), 0.5, 0.75, 1.0, and 1.5 mm. in the subsequent phase, the experiment was extended to examine the combined effects of sa and biochar on the nutrient composition of maize plants exposed to salinity stress. treatments included three concentrations of sa (0, 0.75, and 1.0 mm), three levels of biochar (0, 0.6, and 1.2%), and three salinity levels (0, 4, and 8 ds·m⁻¹) induced by nacl. the findings revealed that under severe salinity stress (8 ds·m⁻¹), seed priming with sa at 0.5, 0.75, 1.0, and 1.5 mm improved germination rates by approximately 18%, 38%, 63%, and 88%, respectively, compared with the untreated control under the same salinity level. the elevated salinity markedly delayed germination and suppressed seedling growth;however, sa application extended the period between the first and the last germination while simultaneously improving seedling height. with increasing salinity, sodium and chloride accumulation in plant tissues rose significantly, while calcium and potassium concentrations declined. the combined application of 1.2% biochar and sa was particularly effective in reducing sodium buildup and preventing calcium depletion under saline conditions. remarkably, at the highest salinity level, the simultaneous use of 1.5 mm sa and 1.2% biochar enhanced potassium content by more than 34% compared with the nacl-only treatment (8 ds·m⁻¹ without sa or biochar). moreover, phosphorus concentration in plant tissues increased by 20% and 44% under salinity levels of 4 and 8 ds·m⁻¹, respectively, relative to the non-saline control. across all salinity treatments, sa consistently promoted phosphorus uptake compared with untreated plants.