I dug this book out, purely on the basis of a review written over at Pechorin's Journal. I concour with everything written there, and in some ways I feel that his comments make my own review superflucous.
Pig Earth is a strange novel. Don't pick it up if you're looking for a nice, simply linear narrative. It's a story, but it's also polemic and poetry. The opening chapter is a Marxist explanation of the role of the peasantry - their social-economic position and their historic position in society. It's useful, and frames what follows well.
The remainder of the book can be viewed as a collection of linked vignettes - linked often by poetry - but more often by characters and places. At the core of the story though, is the struggle for identity. The developing 20th century, the wars it brings to a small peasant village in the French Alps and the changes that result from mechanisation challenge the fundamentals of life for a people who've worked the land for centuries. In some this inspires madness - in others frustrations and resistance - like the farmer who losses his cool and kidnaps the government inspectors.
But the changing world has an inevitability about it, that means an aging peasant population and constant references to the younger people who have left, who won't carry on the old traditions, or even the very farms themselves. Berger's style is beautiful - though I found the poems less interesting than the prose - the last chapter has an air of magical realism, which jarred with the preceeding chapters for me - but that's what happens when you expect a nice, linear tale.