Matt Baker and Ellie Harrison explore the Wolds of East Yorkshire. Matt takes to the Wolds Way national trail to unveil a new land art installation, while Ellie gets an insight into the workings of one of the UK's greatest living artists. For the last few years, David Hockney has painted the Wolds near his East Yorkshire home. Now, ahead of a major new exhibition, he invites Countryfile into his home and his studio for a sneak preview. And he has granted the programme a world exclusive: the first broadcast of a brand new film that forms the centrepiece of his Royal Academy show. Elsewhere, John Craven talks to the prime minister, David Cameron, about some of the biggest issues facing the countryside and the environment in the year ahead. Down his Cotswold farm, Adam has got his work cut out trying out a new sheepdog.