Aside from being a source of wealth, the land exists as its own theme. There is a distinct difference between Yerma's and Juan's relation to the land. In Yerma, the talk of good and bad blood or strong and weak seed is an effort to place the blame for Yerma's barren state. The laundresses cannot agree on whether or not Yerma is at fault. The one who holds Yerma blameless places the fault on Juan for not giving Yerma children.
Destiny is also a common theme in the three plays.
Yerma's problem, in the largest sense, is that she is trying to go against fate, and that is impossible. From Yerma's first mention of how many days she has been married, the reader knows that it is inevitable for her to lead a sterile existence. The theme of death is apparent in the three plays. The intensity of frustration and mounting inevitability are the causes of death in Yerma. What drives Yerma to commit murder is that her husband is not only satisfied but also happy about their childless lives.