agricultural relief

large area of land. held in family trust since 1971. since retirement of tenant in 1986 the land has been farmed by thr trustees. all beneficiaries and trustees do not live on the holding.

do the trustees have to farm the land to retain the agricultural relief afforded on the value of the land. i have come across a note in the inland revenue's handbook that if the land is owned before1976 - be it let or owner farmed - the relief is available. also there is a 7 year rule appicable.

could someone put me in the right irection concerning this.