Killing Heat (1981)

In the 1960s, an American woman relocates from the big city to Southern Rhodesia with her future husband whose farm is failing, giving up all the comforts of cosmopolitan life. Life on the hardscrabble farm eventually takes its toll on her psyche and she finds herself involved sexually with one of their black servants. Based on Doris Lessing's 1950 novel The Grass Is Singing.