By Tom Bill LONDON/DUBLIN, Jan 18 (Reuters) - Land in Ireland earmarked for homes and offices is being sold at knockdown prices to farmers, sometimes the same farmers who made fortunes selling it in the boom years, as swathes of the country return to its agricultural roots. Irish lenders and the country's bad bank, the National Asset Management Agency (NAMA), are cranking up the sale of land to farmers as they accept some locations are dead to developers, even at bargain prices, property agents told Reuters.