X-ray tomography illustrates (in green) the rich complexity of microbial habitat (i.e. pore space) located within the space of a 0.5 cm cube of soil. Theory in soil ecology tells us that soil microbial diversity is largely dictated by the diversity of pore size and pore connectivity. Larger pore sizes may allow for a more robust soil food chain e.g. higher representation of nematodes, collembola (springtails) and enchytraeids (potworms). We can affect habitable pore space in the soil. For example, habitable pore space can be positively affected by organic matter content and negatively affected by soil compaction.