Why is there so many microbes in soil vs air or water?

Answer 1

There are a few reasons for why soil contains significantly more microbes than water and air! Soil often contains a rich variety of organic matter, nutrients, and microenvironments, creating an ideal habitat for microbes to thrive in. In contrast, water and air are less nutrient-dense and have fewer stable conditions for microbes to colonize, leading to a lower microbial population. Soil also offers much more protection against harsh conditions, such as UV radiation, and the variance in soil type among different ecosystems contributes to greater microbial diversity and abundance.