German farmers are to take their tractors to Frankfurt Airport on Saturday, as they continue their demonstrations against cuts to diesel subsidies. According to a police spokesman, the farmers set off towards the airport around 6 am (0500 GMT) on Saturday. A protest drive around the site is planned. Frankfurt Airport’s website was warning travellers to be prepared for traffic disruptions when travelling to the airport. The police expect road closures until the afternoon. The airport operator Fraport is asking people to travel by public transport or to allow extra time for the journey by car. U…