30 soil facts

http://www.soils4kids.org/about
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2731226/
http://forces.si.edu/soils/04_00_01.html
https://www.sciencedaily.com/releases/2016/12/161214085741.htm
http://www.sciencedirect.com/science/article/pii/S0038071714003678
http://www.nature.com/scitable/knowledge/library/soil-carbon-storage-84223790
http://www.dpi.nsw.gov.au/land-and-water/soils/biology/earthworms
https://en.wikipedia.org/wiki/Giant_Gippsland_earthworm
http://www.biokids.umich.edu/critters/Oligochaeta/
http://www.nationalgeographic.com/animals/invertebrates/c/common-earthworm/
http://www.agvise.com/educational-articles/water-holding-capacity/
http://therapeuticgardens.com.au/sensory-gardens-for-individuals-with-dementia/
http://www.fao.org/soils-2015/resources/information-material/en/
http://www.the-scientist.com/?articles.view/articleNo/31879/title/Let-Them-Eat-Dirt/
http://www.fao.org/soils-2015/resources/information-material/en/
https://australianmuseum.net.au/australian-earthworms
http://www.bristol.ac.uk/news/2007/5384.html
https://australianmuseum.net.au/australian-earthworms
http://www.soilhealth.com/soil-health/biology/beneficial/rhizobia/index.htm
http://www.fao.org/soils-2015/resources/information-material/en/