Please get an accountant involved here. It's too complex for an anonymous internet forum.
The change from sole trader to partnership is complicated. I'm assuming a registered farm partnership here?
The partnership must prepare accounts in its own right, and the individual partners pay tax on their individual share of the profits. So the capital allowances on partnership assets should be used by the partnership, and the resulting profit shared to each partner based on partnership agreement. But there are further complex rules, such as capital allowances not being used to increase a loss, and rules around carrying forward capital losses.
There is some Revenue guidance, but talk to whoever advised on the original creation of the partnership.