稻鸭萍共作复合生态系统的物能特征分析

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

对稻鸭萍共作生态系统物能流特征的分析结果表明,通过在稻田生态位添加鸭子和绿萍,使原来的稻田食物链结构趋向复杂化,增加了稻田生态系统的稳定性。稻鸭萍共作生态系统光能利用率最高,比稻鸭共作生态系统和常规稻作系统分别提高18.52%和23.08%;能流循环指数为0.096,显著高于稻鸭共作系统和常规稻作系统。此外,稻鸭萍共作生态系统氮磷钾各养分循环通量也表现为最高,显示稻鸭萍共作生态系统农田养分循环强度较高,对施肥的依赖程度较低,对环境压力小。

This article studied the characteristics of substance and energy in rice-duck-azolla integrated fanning （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.