Oxygen measurements in a mushroom compost stack

Oxygen concentrations and temperatures were measured in 9 representative regions of a section of a mushroom compost stack, to determine the relative rates of utilisation of oxygen by micro-organisms and replenishment of oxygen by movement of gases through the compost.Distinct patterns of change in oxygen concentration were identified. Oxygen concentration, integrated over the whole composting-time, was greater than 5% in 86% of the stack volume, but temperatures were above optimum for growth of thermophilic micro-organisms for most of the composting-time in 60% of the stack volume.