Her story is simple.
Her protagonist is a simple man trying to get rich, though we learn how complex even the lives of simple farmers in pre-revolutionary China can be.
Her sentences also appear simple, but they are not. They are elegant. Other online analyses of this novel (here and here) explain the sagalike, biblical quality of Buck's sentences. As
Most of Buck’s sentences are long and serpentine, relying on balance, parallelism, and repetition for strength.Here's an example:
Spring came in long, warm days scented with blossoming plum and cherry, and the willow trees sprouted their leaves fully and unfolded them, and the trees were green and the earth was moist and steaming and pregnant with harvest, and the eldest son of Wang Lung changed suddenly and ceased to be a child.Nasrullah hits on the serpentine-ness of the sentences, on their balance and repetition. But, to put it another way, balance and repetition are to me just characteristics of lingual rhythm. The rhythm is the secret. Rhythm, stepping to the length of the sentences, beating to their conjunctions, rhyming with their repetition.
A saga is a song—no?
Buck uses her sentences to create the feel of her book. It's slow determination. It's steady forcefulness that glides the reader forward through the long sentences, down the wide, rich river of the story, chapter by chapter, until it ends in an ocean of thought and contemplation, on the irony of all life's efforts ending in death.
Different stories may have different rhythms. They may go chop, chop, chop in short, declarative statements. Or they may go long-long, long...long-long, long...long...long...long. In whatever form your sentences may be structured—whether as long sentences, like Buck's, where we risk falling into pits of conjunctivitis (too many ands and buts and such), or as (so-called modern) short sentences—it's the rhythm that makes or breaks them.
Try it out with your own speech. How many clauses and subclauses do you string together when you talk? How complex do your spoken sentences get? I assume people understand you when you speak—right?
Also, try out onomatopoeia, such as in Buck's example. Why would she craft and use this (some would label) run-on sentence? What is she describing? What rhythm is she trying to get across and what image/emotion/message is she trying to transmit with it?