A Comprehensive Approach to Ameliorate the Solo and Mutual Toxicity of Cadmium and Tetracycline Antibiotics in Maize ( Zea mays L.) Crop Through Nutritional Spray of Ca–Mg Nanocomposite

The accumulation of antibiotics and heavy metals in agricultural land has become a pressing concern due to industrialization and the widespread use of manure as fertilizer. The primary purpose of this study is to estimate the solo and joint effects of tetracycline (TC) and cadmium (Cd) on maize plants, as well as the efficacy of Ca–Mg nanocomposite in mitigating these stresses. A pot trail was executed using a complete randomized design (CRD) with seven treatments: T0 (control), T1 (TC 8 mg·kg −1 ), T2 (Cd 50 mg·kg −1 ), T3 (TC 8 mg·kg −1 + Cd 50 mg·kg −1 ), T4 (Ca–Mg nanocomposite 100 mg·L −1 ), T5 (TC 8 mg·kg −1 + Ca–Mg nanocomposite 100 mg·L −1 ), T6 (Cd 50 mg·kg −1 + Ca–Mg nanocomposite 100 mg·L −1 ), and T7 (TC 8 mg·kg −1 + Cd 50 mg·kg −1 + Ca–Mg nanocomposite 100 mg·L −1 ). The outcomes indicated that the combined stress of TC and Cd significantly reduced the activities of antioxidant enzymes, such as peroxidase (POD) (27.1%), superoxidase (SOD) (26.1%), catalase (CAT) (27.2%), and ascorbate peroxidase (APX) (50.9%). However, nutrient‐based foliar spray of Ca–Mg 100 mg·L −1 nanocomposite effectively reduced oxidative stress parameters, such as malonaldehyde (MDA) (3.9%) and hydrogen peroxide (H 2 O 2 ) (7.2%), and decreased metal uptake in roots (57.1%) and in shoots (63.1%). It was estimated that Ca–Mg nanocomposites can be a useful tool for mitigating the antagonistic effects of heavy metals and antibiotics on maize plants and highlight the potential of nanotechnology in developing sustainable solutions for environmental remediation.