Effects of biochar application on soil properties and the growth of Melissa officinalis L. under salt stress

Soil salinization is one of the world's most seriously ecological issues. The application of biochar may enhance the properties of the soil and lessen the harm that salt stress causes to plants. In this study, we used the cuttings of Melissa officinalis as experimental materials. The method of pot experiment was used to explore to explore the effects of different concentrations of biochar (0, 10 %, and 20 % w/w) on soil properties and plant physiological characteristics under salt stress (0, 0.20 %, and 0.60 % NaCl+Na₂SO₄). The results indicate that the physicochemical properties of soil and the plant growth were decreased impacted with increasing salinity level, and these negative impacts were decreased traits were improved with the application of biochar. It was discovered that the application of biochar could increase the soil water holding capacity, total porosity, available P and K content, and soil enzyme activity while also decreasing the soil bulk density under salt stress. Biochar addition promoted the accumulation of plant biomass and the acquisition of nutrients, and reduced Na content in plants. With the addition of biochar, malondialdehyde (MDA) content and electrolyte leakage displayed a significant decrease under salt stress. A reduction in the osmotic substances and secondary metabolite accumulation in the leaves was also evident. The presented results reveal that biochar can contribute to protect M. officinalis against salt stress by alleviating the oxidative stress. Among the test samples, the 20 % biochar application had the best performance, suggesting that this is an advantageous method for improving soil properties and lessening the harm caused by salt stress on M. officinalis.