Actually, a major issue is the large amount of methane gas from that manure pile. One little spark and a major fire erupts.
Do you know that for a fact? I realize that anaerobic decomposition produces methane - but assume that it would immediately dissipate (it's lighter than air). A certain high concentration of methane would be needed for ignition. Only in an enclosed area or gas-tight container would that be possible.
As I said: I'm familiar with spontaneous combustion - but that is something other than the spark-ignition of methane - which I think would, in actual practice, be difficult to achieve.
Regards,