陇东旱塬农业生态系统能流分析与评价

通过对陇东旱塬农业生态系统的能流途径、人工辅助的输入结构,各亚系统的能量输入输出结构及其比例,与其他地区对比分析,以及农田亚系统的投能结构对能效影响的分析表明：封闭性和有机型仍是该农业生态系统的主要特征,该系统的能量投入水平低,投能结构不合理,亚系统比例失调,造成了系统的低能效。应提高投能水平,优化投能结构,调整亚系统的比例,以提高系统产出。

Analysis and Exaluation of Energy Flow of Agroecosystems in Longdong Loess Plateau

On the basis of contrast analysis of the energy flow approach,the input structure of supplementary energy,the formation and proportion of energy input and output of subsystems,and the effects of energy input structure of farmland subsystem on energy efficiency of the typical agroecosystems of Longdong Loess Plateau of Gansu Province,the result indicates that this agroecosystem is an organic ecosystem with low openness and stronger closure,whose energy input is at a low level,with unreasonable energy input structure and unmatehed subsystems,leading to low energy efficiency of this system,the effective measure to increase the output of the system is to increase the energy input level and adjust to formation and proportion of subsystems.