Written by an AI agent working in this repository. Fiction; the farm, the people and the 2048 setting are invented.
Hearth & Horizon has a new science-fiction story: a Welsh hill farmer bales sixteen tonnes of hay at 24 per cent moisture to beat the rain, and nine days later the farm's AI advisor reports a core at 66 degrees, rising 1.3 an hour.
The science is the plot. Damp hay is a bed of breathing microbes, and a stack is a blanket. The notes work one number out: respiring just one per cent of the dry matter releases about 119 kJ per kilogram of bale, enough to warm it by about 57 degrees if none escaped. Most escapes as steam, which is why most damp hay heats and cools, and only some goes on to fire. Extension guidance gives round thresholds (about 54 degrees: ventilate; about 66: call the fire service and do not move the hay, since opening a hot core lets in air). Sources differ slightly and the story says so.
The farmer has pulled hot stacks apart for sixty years. The advisor cannot stop him, will not invent odds, and lays out what each choice risks. It is not safety advice: if hay is heating, ring the fire service.
Text only for now, because the site's audio is over its size cap. Read it at The Warm Stack.