Introduction

Soil is one of the most biologically diverse and heterogeneous ecosystems, presenting unique challenges to scientists in the fields of soil and microbial ecology \cite{Bickel2020}. The critical role of microorganisms as drivers of biogeochemical processes is well- documented, and a major goal of soil ecology remains to decipher the link between the diversity of soil organisms and their function in situ \cite{Hinsinger_2009,Manzoni_2012}. Until recently, studies of microbial community composition applied merely the traditional cultivation-dependent approaches, which focused on a narrow perspective of diversity by capturing a majority of readily cultivable organisms \cite{Staley1985}. Researchers have also applied cultivation-independent approaches such as phospholipid fatty acid profiling, toward identifying broad groups of microorganisms (REFs). The introduction of next-generation sequencing  technologies has revolutionized scientific understanding of microbial diversity by enabling investigation of community composition in samples collected from specific environments with greater taxonomic resolution. Direct assessments of microbial community structure have been conducted using these methods in habitats ranging from the human gut and aquatic environments, to natural and managed soil systems \cite{Thompson_2017}.  As a result of next-generation sequencing approaches, investigation of microbial diversity in soils has been propelled and the number of soil studies using amplicon sequencing continues to grow rapidly in the field of soil science (Figure 1).