秸秆能源化利用中资源供应持续性分析

Analysis on Sustainability of Crop Residue Supply in Its Energy-oriented Utilization

秸秆是一种重要的生物质能源原料,对其资源进行评价是很多研究所关注的问题。农作物收获具有明显的季节性,使得秸秆供应持续性及其影响因素成为突出的问题,但研究上尚未对此予以充分关注。本文首先从理论上分析了地理气候条件、宏观经济状况、种植业产业特征三大类因素对秸秆供应持续性的影响,并基于2005-2009年全国31省市面板数据,运用FGLS模型验证理论分析提出的推论。结果表明:种植业规模、作物多样性、气候条件和平原地形对持续性具有显著的正向影响,蔬菜比重、气候条件平方项、能源压力和经济水平对持续性具有显著的负向影响。进一步采用回归分解方法测度各因素对省际持续性差异的贡献率,发现考察变量对省际持续性差异的解释程度达到80%,分解模型具有较好的解释力。种植业产业特征变量对持续性的影响大于地理气候条件和宏观经济因素变量,种植业特征对持续性解释力占所有解释变量的48%,宏观社会经济条件解释力次之,占36%,地理气候条件解释力较低,仅占16%。从单个因素来看,经济水平差距是造成东部省份与中西部省份持续性差异的最重要的因素,除此之外作物多样性和作物播种面积对省际持续性差异解释分别达到18%和12%,气候条件、能源压力、种植业结构、地形和复种指数的解释力依次降低。因此,提高供应持续性应重点从调整种植业产业特征方面入手,农业大省应充分发挥资源优势,开发秸秆能源功能,加大耕地保护力度,稳定种植业规模,保障秸秆资源总量,并进一步提高农作物种植的多样性。

As important biomass energy raw materials, straw resources and its evaluation have climbed into important research agenda. Obvious seasonality in crop harvest makes sustainability of straw resources supply a great concern. This paper firstly theoretically analyzes the impact of geographic and climate condition, macroeconomic status, cropping feature on straw resources supply sustainability. The paper further checks the deduction from theoretic analysis by using a panel data of 31 provinces in China from 2005 to 2009, and employs FGLS model to analyze the influencing factors. The results show that cropping scale, cropping diversity, climate condition, and plain terrain have significant positive impact on straw resource supply sustainability, while percentage of vegetable area, square term of climate condition, energy supply pressure and socioeconomic status have negative impacts on sustainability. Furthermore, a regression-based decomposition method is employed to measure the contribution of each factor to the provincial disparity of straw resource supply. It finds that the model is of good explanatory power since observed variables can explain 80% of the disparity. Cropping feature variables have more impacts than geographic-climate and macroeconomic variables, and its explanatory power occupies 48% of all variables. The explanatory power of macroeconomic variables and geographic-climate variables occupies 36% and 16%, respectively. Socioeconomic factor is the major factor that made sustainability of straw resource supply in eastern provinces lower than that of central and western provinces. Cropping diversity and cropping scale respectively contribute 18% and 12% variation of provincial sustainability. The explanation power of climate condition, energy supply pressure, cropping structure, terrain situation, and cropping index declined accordingly. Thus, adjusting the cropping feature is important to improve straw resource supply sustainability. In order to keep straw resource resource supply, agriculture-based provinces should take advantages of straw resource supply, protect cultivated land, fix crop area, and further improve cropping diversity.