I'm blown away by the level of ignorance about farming among the commentariat since the UK IHT changes were announced. People talking about 'farms' as if they're all interchangeable. There's a huge difference in scale between a dairy farm in Devon, a sheep farm in Cumbria, and an arable farm in Suffolk.
Where a dairy farm may be able to function at around 250 acres and fall below the IHT band, an arable farm needs to be around 600-800 acres to be viable.