There are many social and/or professional networks all over the world wide web where you can share your thoughts and ideas about a given subject. A quick search through those will show that earth architecture is usually present in the form of a specific discussion group.
Linkedin is no exception. In fact, there are a few groups dedicated to earth architecture and construction - Earth architecture group, Earth buildings, Mudobe, rammed earth specialists, and others. So, to add to this list, I have just created a group called Earthen architecture in Portugal | Arquitectura de terra em Portugal. Please, do feel free to join in and also bring your valuable contribution to the group!