FaRMERS will be expected to do more to protect the environment in future if they want European subsidies, a minister is to warn.  In a speech to the Oxford Farming Conference on Wednesday, Caroline Spelman, the Environment Secretary, will set out Britain's position on reform of the Common agricultural Policy (CaP).  The scheme has long been criticised for producing grain mountains and butter lakes. Mrs Spelman will say that in future subsidies should be focused on "public good" so that farmers are paid for looking after the landscape, in addition to a basic rate of income support.  She will als