Build Farmland for Engineers on irrigated desert is greyed out, even though the help for Desert indicates Build as Irrigation Farmland 5 turns. Helps for Engineers and Terrain Alterations->Farmland give no indication of exclusion of desert as a farmland candidate.
Please, advise: is this a bug?
civ2civ3 Engineers Not Able to Irrigate Desert to Farmland?
Re: civ2civ3 Engineers Not Able to Irrigate Desert to Farmland?
It's intentional because it would not give more food and would prevent super highways trade bonus. You can get desert/farmland from global warming but can't make it yourself. The automatic documentation probably misses some complex cases, maybe one should document it manually.