**2.3 Experimental design**

A greenhouse pot culture experiment was conducted at Felix Houphouet-Boigny University, Cocody, Abidjan, Ivory Coast, to study the effect of *Bradyrhizobium* ORS and earthworms (*P. corethrurus*) on the growth and phytoremediation capacity of *A. mangium*. The average temperatures in the greenhouse were 26, 38, and 32°C for morning, afternoon, and evening, respectively. The experiment was carried out using four treatments:


The experiment was conducted for 90 days, and each treatment was carried out in triplicate. Before filling the pot, it was perforated to allow aeration and then covered with a perforated filet to prevent the earthworms from escaping. The pots were placed in a factorial arrangement based on a completely randomized bloc design. The seedlings were watered daily with deionized water to maintain the moisture content at approximately 60% water-holding capacity of the soil.
