A group of arable farmers in Norfolk, whose land covers 10 thousand hectares along the River Wensum, say they are being wrongly blamed for water pollution. Over the last 18 months the Wensum Group Farmers have employed an adviser to help them farm in a way that reduces pollution from their fields, and take regular samples of water for phosphate and nitrate levels. A report by the government's Environment Agency and Natural England found 30 percent of pollution in the river Wensum was caused by farmed land. Now the farmers' group is challenging the government's model. And we visit a demonstration farm run by Anglo Beef Processors (ABP) - the largest beef processor in Ireland and the UK. They’ve been working to reduce the ‘emissions footprint’ of cattle. Presented by Caz Graham Produced for BBC Audio in Bristol by Heather Simons