[1] Furthermore, bulk soil inhabitants are generally smaller than identical species in the rhizosphere.
[2] The main two aspects of bulk soil are its chemistry and microbial community composition.
Chemical properties of the bulk soil are organic matter, carbon, nutrient content, cation-exchange capacity (CEC), free ions (cations or anions), pH, and base saturation and organisms.
These can impact many chemical processes such as nutrient cycling, soil formation, biological activity, and erosion.
Soil is composed of a diverse community of microbes such as: fungi, bacteria, archaea, viruses and microfauna.