36-Embracing the unknown disentangling the complex

36-Embracing the unknown disentangling the complexities of the soil microbiomeHowcanIstandonthegroundeverydayandnotfeelitspower?HowcanIlivemylifesteppingonthisstuffandnotwonderatit?—W.B.Logan1Soilmicrobialbiomassrivalstheabovegroundbio-massofplantsoranimals,withsoiloftencontaining>1,000kgofmicrobialbiomasscarbonperhectare2,3.Thesesoilmicroorganismshavecrucialrolesinnutrientcycling,themaintenanceofsoilfertilityandsoilcarbonsequestration,andthesoilmicrobiomehasbothdirectandindirecteffectsonthehealthofplantsandanimalsinterrestrialecosystems.Theimportanceofthesoilmicro-biomehasbeenrecognizedformorethanacentury4,andthereisalonghistoryofresearchthatdescribesthemicroorganismsthatinhabitsoil,theirmetaboliccapa-bilitiesandtheirinfluenceonsoilfertility.Infact,manyoftheimportantdiscoveriesmadebymicrobiologists—includingthediscoveryofantibioticsanduniquemicrobialmetabolicpathways(forexample,nitrogengasfixationandammoniaoxidation)—werelargelyderivedfromworkwithsoilmicroorganisms.Recentmethodologica