关键词: 大豆连作障碍, 土壤酚酸

Abstract: Mulberry-silkworm ecosystem is one of the important agro-ecosystems in China.Based on the principles and methods of emergy analysis,this paper studied the interior structure of mulberry-silkworm ecosystem and its relationship with exterior environment and economy.Some emergy indices for this ecosystem were quantitatively calculated,and compared with those of the agro-ecosystem in China.The results showed that the emergy investment ratio,emergy yield ratio,environmental loading ratio and emergy sustainability index was 3.78,4.68,0.18 and 26.0,respectively,suggesting the low environmental pressure and good ecological benefit in mulberrysilkworm ecosystem in China.Hi-technology was required to further decrease the labor force input and enhance the comprehensive utilization of sericultural resources.

Key words: Continuously cropping soybean obstacle, Soil phenolic acids