Triticale and oats showed the best estimated maximum methane potential per hectare when cultivated under non-irrigated conditions in Spain, both with potentials over 1,000 Nm3 CH4/ha. Barley showed good biodegradability but had a lower potential per hectare. A mixture of ryegrass and clover was not suitable, with a low potential of 264 Nm3CH4/ha. Triticale demonstrated the highest potential per hectare, per kilogram of seeds, and per liter of rainwater, making it the most suitable crop under the dry conditions studied.