Guidelines for synergetic utilization of Chinese agricultural land based on the emergy balance law

With the emergy balance law as theoretical support, the basic principle to guide synergetic utilization of agricultural land with the emergy balance law is expounded by defining the basic connotations of that theory, and emergy indexes of Chinese agricultural land system are established; the synergetic degrees of China´s agricultural land system in the past 10 years are judged so as to form a new idea on the synergetic utilization of Chinese agricultural land. The results show that: the synergetic degree of China´s agricultural land system is decreased year by year, which is mainly shown in the fact that a high output is based on a high input despite a basically balanced status of emergy input and output of China´s agricultural land system. Moreover, the pressure of adverse environmental impact of excessive fossil energy on the agricultural land ecological system keeps rising. Therefore, only by adjusting the structure of China´s agricultural land based on the emergy balance law can the dual functions of land as a resource product and for ecological services be maintained and can existence of the synergy of the ecological system of China´s agricultural land be guaranteed.