Characteristics of substance and energy in rice-duck-azolla integrated farming system

This article studied the characteristics of substance and energy in rice-duck-azolla integrated farming (RDA) system. RDA system increases food-chain complexity and system stability because ducks and azolla are incorporated into rice paddy systems. Light utilization efficiency is highest in RDA, with respectively 18.52% and 23.08% higher than in rice-duck integrated farming (RD) and conventional farming (CK) systems. Energy circulation index in RDA is 0.096, significantly higher than in RD and CK. NPK flux is highest in RDA, implying that cycling intensity and recycled farmland nutrients are higher in RDA. RDA depends less on fertilizer and is therefore more friendly to the environment.