Precambrian evolution of the nitrogen cycle

Nitrogen is the main constituent of Earth's atmosphere and is a critical nutrient for life. The focus of this chapter is on the evolution of the N cycle on Earth during the Precambrian (4.56 to 0.541 Ga). We discuss tools and approaches for studying past N cycling, as well as the evolution of the biologic, atmospheric, and solid Earth cycles. Within each section, we describe the current understanding of each field and highlight knowledge gaps for future work. We also provide some historical context for the study of N in the rock record.