Deforestation (disafforestation) The permanent removal of forests, especially by means of logging for commercial timber and clearing for agriculture and human settlement.
The phenomena of agroecological environment are becoming worse and worse in the arid and semi-arid regions that has become the predominant obstacle for agriculture development.
Chapter four is the research on diversity architectures of agriculture technique extension mode, analyzing the necessity that diversified mode constuct. several magistral modes is comparative studied.