"Flanders needs farmers to produce their food. But farmers need a future also," says Lode Ceyssens, president of the Flemish agricultural union Boerenbond. Slow-moving convoys of some 2,700 tractors block roads in Brussels as farmers from the Flanders region protest at moves to cut nitrogen emissions. The production and use of nitrogen fertilisers generates climate-warming greenhouse gas emissions, as does livestock waste. IMAGES AND SOUNDBITES