There are a number of reliefs available to you.
First of all there is no stamp duty on death so you first relief sorted!
Secondly, If 80% of your assets after taking the gift, are farming assets (including farmhouse) then you can qualify for agricultural relief which will reduce the value of your inheritance by 90%. You can deduct your mortgage from your own private house for this purpose. Remember you could qualify for agri relief depending on the agri. value placed on the farm. It could be 6000 per acre or 15000 per acre depending on location etc and a clever accountant who knows farm tax and a good valuer and solicitor will work together on this issue.ie It may be worthwhile to place a higher value on the farm in order to get the agri. relief.
Failing the above you could also get business relief but be carefull with this one as your uncle must have been farming (not leasing his lands) and you also have conditions to satisfy.
You could also be entitled to favourite nephew relief, which will treat you as a son. For this you must show that you worked substantially on a full time basis (15hours per week) for the previous five years on the farm.
Favourite nephew relief plus green cert plus agri relief generally means no tax, so work on it.