Hello, I'm Keith and happy to help you with your question.
Firstly there is no CGT on death, all the deceased assets being aggregated and subject to IHT. Anything over 325K is taxed at a flat rate 40% unless more than 10% of bequests are of a charitable nature when the rate falls to 36%.
However, in general terms agricultural land passes outside the IHT envelope. You can read all about the terms and conditions here:
but I think you will find the preamble covers the matter; here is the relevant extract:
'You can pass on some agricultural property free of Inheritance Tax, either during your lifetime or as part of your will
Agricultural property that qualifies for Agricultural Relief is land or pasture that is used to grow crops or to rear animals intensively.
It also includes:
I do hope I have been able to set your mind at rest on this matter.