1. Disclosure requirements: In FA schedule Impairement loss should be shown in a seperate coloumn (next to current year depreciation coloumn) and the basis for the impairement loss should be shown by way of note under the financial statements (say, impairement is done based on a technical valuation by management, independent surveyor etc.)
In notes to accounts, under the head Fixed assets and depreciation you have to mention that FA are stated at cost less depreciation, impairement (if any). Also you should state that on each balance sheet date assets are reviewed for indications of impairement and inpairements are recognised in the books.
2. Treatment in subsequent years: Impairement loss should be treated just like depreciation. The gross block value of the assets will show the original cost of acquisation and the impairement loss will not be reduced from the cost.