‘Like a giant sewage plant’: how Germany’s ‘pig belt’ got too big

In some areas in Lower Saxony – home to more than 7 million pigs – the density of pigs is four times the national average. Photograph: Henner Rosenkranz

There is an old saying, rather unloved by local people, that if you roll down the window while driving through Germany, you’ll always know from the smell when you are in Lower Saxony.

This is the heartland of a €6bn (£5.1bn) pork industry that sends thousands of tonnes of German pigmeat across the world. But it has done so at a cost. Maps of the Schweinegürtel (pig belt) glow a toxic red if you show ammonia emissions from farm animals and nitrates in groundwater.