The perseverance of your dry mass of all substrate pots by drying within a ventilated oven at 60°C (Heraeus, Hanau, Germany) for 7 times at first and finish of lettuce cultivation allowed the calculation with the mineralized organic matter throughout the experiment. This method was used based on the strategy https://knoxukxkw.madmouseblog.com/13501441/5-tips-about-ventilation-system-you-can-use-today