What are 4 ways bacteria, fungi, mites and springtails aid in soil fertility?

has to do with chapter 5 of the book silent spring by rachel carson.What are 4 ways bacteria, fungi, mites and springtails aid in soil fertility?
Nitrifying bacteria convert nitrogen gas (N2) into nitrate, a form plants can take into their roots.





Many soil fungi produce antibiotics that keep harmful fungi and bacteria from growing in the soil.





Mycorrhizae are mutualistic associations between a plant and a fungus that benefits both species. The fungi are better at taking up certain nutrients than the plants are, and the plants supply carbohydrates from photosynthesis to the fungi.





I'm not sure about mites specifically but many invertebrates, fungi and bacteria break down organic matter into smaller bits which plants and other organisms can use. For example a leaf composed of lignin and cellulose is difficult for most organisms to break down. Certain organisms that can break it down release forms of carbon, nitrogen, phosphorous and other macro- and micronutrients that many more organisms can use.





I have not read this specific book so I'm not sure what Carson covers. Since this book relates to pesticides and environmental pollution she may have covered bioremediation. Certain bacteria, archaea and other organisms can break chemicals that are harmful to most life forms, effectively removing them from the environment. Deinococcus radiodurans (http://en.wikipedia.org/wiki/Deinococcus鈥?/a> ) is one very interesting example. There are other prokaryotes that can break down aromatic hydrocarbons, halogenated organic molecules, heavy metals, solvents and all sorts of other toxic chemicals.