The following list is far from exhaustive.

Permaculture/natural farming

Brin de Paille (association) : asso.permaculture.fr
El portal de permacultura en lengua española : Permacultura ES

Natural Hygiene and health

A. Mosséri : http://www.hygienisme.org
Désiré Merien : http://www.desiremerien.fr

Wwoof/Exchange’s networks

Espana : http://ruralvolunteers.org/WHOSTS/
International : http://www.wwoofinternational.org/
HelpX : http://www.helpx.net

Water management

Joseph Országh (scientifique) www.eautarcie.com,
« Eau vivante » (association) http://eauvivante31.free.fr

Ecolieux

Oasis Bellecombe (Alps, France) http://www.oasisbellecombe.com/

Others links

Town hall (ayuntamiento) of Maella http://www.maella.es/
Qi gong et developpement personnel www.mantha-eden.net/