About 6 kg of soil samples were sieved using 2 mm mesh size and transferred to polyethylene packets, tolerant
to high temperature, and saturated with water for 48 hours. The soil samples were transferred to the autoclave
(SS-325-Automatic High-Pressure-Steam Sterilizer Class I-B) and kept inside the autoclave at 120˚C for 1.5
hours. Then the soil samples were left for cooling. The cooled soil was transferred to black plastic pots having 4
holes in the bottom, for the execution of the experiment.