Improving wheat physio-biochemical attributes in ciprofloxacin-polluted saline soil using nZVI-modified biochar

The Ciprofloxacin (CIP) toxicity and salinity stress in agricultural soils cause risk to environmental and food safety. Consequently, it is essential to devise or use more effective techniques for mitigating salinity and ciprofloxacin-induced stress in soil. This study includes the nZVI-loaded biochar synthesis, integrating the unique characteristics of raw biochar with nZVI. The present study examined the impact of raw and nZVI-loaded biochar on soil quality and the mitigation of salinity stress and Ciprofloxacin toxicity in wheat plants. The results showed that the application of nZVI-loaded biochar treatments led to substantial enhancement in shoot biomass, root biomass, grain biomass, and spike biomass by 152.1, 54.3 %, 59.8 %, and 151 %, respectively compared to control treatment. The treatment with nZVI-loaded biochar significantly increased the rates of photosynthesis and transpiration, as well as the conductance of stomata. It also resulted in higher levels of intercellular CO₂, photosynthetic pigments, and water use efficiency with increases of 49 %, 59 %, 57 %, 37 %, 40 %, and 95 %, respectively. The nZVI-loaded biochar significantly decreased electrolyte leakage, malondialdehyde (MDA), and hydrogen peroxide levels compared to the NaCl treatment alone. It also enhanced the activities of enzymatic antioxidants such as peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX). The non-enzymatic antioxidants including total soluble sugars (TSS), flavonoids, total soluble proteins (TSP), phenolics, ascorbic acid, anthocyanin, proline, and glycine betaine significantly influenced by the nZVI-loaded biochar. The nZVI-loaded biochar effectively alleviates the stress of soils that are contaminated with hazardous amounts of Ciprofloxacin while improving the soil and plant health.