The disinfection in the autoclave alters the chemical and physical characteristics of the soil, in addition to eliminating the organic matter and microorganisms of the same
With the treatment in autoclave, all the microbiota is eliminated in such a way that the processes mediated by them in terms of transformation and recycling of nutrietes
are going to stop, you can also destroy the structure of small organic molecules that may eventually be important in aspects such as cell communication between plant and microorganisms, hormones etc. can also alter molecules that play a role in the aggregation of soil, also the transformation of certain organic molecules could generate new undesirable compounds (eg microbicides or phytotoxic). thermolabile forms of some nutrients such as N and P can also be altered.
In this way, you can "build" yourself the substrate by adding the support (beads or sand). Then you can autoclave your system and keep it very well closed. Finally, you can add the needed nutrients for the plants by injection using 0.2 µm filters that eliminate all infections.
Further manipulation should be done under a hood and the seeds of the plants can also disinfected.
Maybe there is a part where i will work in hydroponic condition, but i want to study the effects of interaction between the three elements : soil-bacteria-plant, so i have to work with soil
This issue, we ahve already discussed at length at RG but under umbrella of solarisation/sterilization. Surely soil disinfection does change soil ecology a great deal , thereby , chemical and physical properties of the soil undergo changes , quite distinct from non-disinfected soils. Here you mean soil disinfection synonymous to sterilization..?
Its very difficult maintain orignal soil chemical and biological properties , unless the autoclaving condifions are defined. Under normal autoclaving conditions, I doubt too many soil properties will change so drastically ....