基于能值理论的秸秆利用生态足迹评估--以成都平原典型稻麦轮作区为例

本文采用能值分析与生态足迹分析相结合的方法,以成都平原典型稻麦轮作区——广汉市和大邑县为例,对研究区各种利用方式的秸秆资源进行能值评估,并采用能值生态足迹方法对区域秸秆利用的人均生态足迹及人均生态承载力进行分析。结果表明,2011年广汉市稻草和麦秆利用的人均生态足迹分别为0.066 1 hm2和0.034 2 hm2,人均生态承载力分别为0.083 9 hm2和0.042 3 hm2,人均生态盈余达0.017 8 hm2和0.008 1 hm2,其中稻草不同利用方式的人均生态足迹表现为肥料化原料化焚烧及其他饲料化沼气化,麦秆表现为肥料化焚烧及其他原料化沼气化饲料化;2011年大邑县稻草和麦秆利用的人均生态足迹分别为0.051 6 hm2和0.020 9 hm2,人均生态承载力分别为0.061 0 hm2和0.021 7 hm2,人均生态盈余达0.009 4 hm2和0.000 8 hm2,其中稻草不同利用方式的人均生态足迹表现为原料化肥料化沼气化焚烧及其他饲料化,麦秆表现为肥料化焚烧及其他原料化沼气化饲料化。这表明广汉市和大邑县的秸秆利用还存在一定程度的消纳空间,尤其是现有秸秆处理结构中未经合理利用甚至废弃的秸秆资源,如能充分再利用,必定会带来显著的社会经济效益和环境生态效益。

Evaluation of ecological footprint of straw resources utilization based on emergy theory: A case study of typical rice-wheat rotation region in Chengdu Plain

Using Guanghan City and Dayi County as typical regions of rice-wheat rotation system in Chengdu Plain, emergy and ecological footprint theories were applied in the determination of the utilization status of straw resources based on statistical and survey data in 2011. Firstly, the emergies of different ways of straw utilization were calculated and the values of ecological footprint and capacity per capita then estimated and analyzed using the ecological footprint analysis method. The results showed that the values of per capita ecological footprint of rice and wheat straw resources in Guanghan City were 0.066 1 hm² and 0.034 2 hm² and the per capita ecological surpluses corresponding were 0.017 8 hm² and 0.008 1 hm², respectively. As for different utilization ways, the ecological footprint per capita of rice straws was in the order of fertilizer > raw materials > incineration and other ways > feed > biogas; for wheat straws, it was in the order of fertilizer > incineration and other ways > raw materials > biogas > feed. The values of per capita ecological footprints of rice and wheat straw resources in Dayi County were 0.051 6 hm² and 0.020 9 hm² with corresponding per capita ecological capacities of 0.061 0 hm² and 0.021 7 hm² and per capita ecological surpluses of 0.009 4 hm² and 0.000 8 hm², respectively. As for different utilization ways, the ecological footprint per capita of rice straws was in the order of raw materials > fertilizer > biogas > incineration and other ways > feed; for wheat straws it was in the order of fertilizer > incineration and other ways > raw materials > biogas > feed. The above results indicated that there still existed some room for reutilization of straw resources in Guanghan City and Dayi County. Specifically, if the unused part of the current straw resources were reused fully, it would greatly promote agricultural development which could lead to significant economic, ecological and environmental benefits.