Nitrogen Fertilizer Enhanced the Vitality of Oregano (Origanum vulgare) Plants and Boosted Their Ability to Accumulate Soil Cadmium: Agro-environmental Implications

Soils with high cadmium (Cd) content can be decontaminated with phytoremediation. In this work, we aimed at adding nitrogen (N) fertilizer for enhancing the vitality of our test plant, oregano (Origanum vulgare). In a pristine soil, we added Cd at 0, 20, and 40 mg kg−1 soil (thereafter Cd0, Cd20, and Cd40) and two N rates at 0 and 340 kg N ha−1 (thereafter N0 and N1) in a 75-day pot experiment. We found that oregano dry weight increased significantly from 4.95 at control to 7.34 g pot−1 at Cd40N1 (a 148