Leaving the Land

by Douglas Unger. Harper & Row, $13.95. Mr. Unger’s novel, set in the Dakotas, records the decline of a once-prosperous farming family reduced to what amounts to peonage by a combination of misguided federal policy and big-money agribusiness. The Hogans are plausible characters and the author has worked hard to make them interesting, but they remain imaginary, while the financial and legislative network that entraps their entire region is real and has its sinister counterparts in other rural areas. The background of the tale therefore becomes more important than the experience of any character, producing the impression that the author is aiming at the wrong target. This is a first novel, and although out of balance, it is intelligent and promising.