干旱半干旱地区城郊农业生态系统的能值分析与优化发展——以乌鲁木齐市为例

乌鲁木齐市农业生态系统是我国干旱半干旱地区典型的城郊农业生态系统。应用能值分析的理论与方法,可以更加本质的了解该农业生态系统的发展现状与影响该系统可持续发展的障碍。通过分析表明:(1)在能值投入中,以水资源为主的环境能值投入较大,而可更新的有机能所占比例较小。与干旱半干旱区其它地区的农业生态系统相比,乌鲁木齐市农业生态系统的能值自给率、能值密度处于比较优势,而可更新有机能/总能值与能值投入率处于比较劣势地位。今后,应当继续优化能值投入结构。(2)在能值产出中牧业能值产出较大,系统生产优势度明显,但各生产系统之间的耦合力仍需加强,农户的经济生产力水平有待进一步提高。今后,应调整农业产出结构,实现各级生产力的最大程度耦合。(3)通过总的比较来看,城郊农业生态系统有着较低的能值投入,较高的能值产出和较强的可持续发展能力,在干旱半干旱区应当大力发展城郊农业,以增强农业的产出能力和基础地位。

Energy analysis of suburban agro-ecosystem and optimization development in arid and sub-arid region: A case in Urumqi

Agro-ecosystem in Urumqi is representative one of outskirts of a city.In sight of the theory and method of energy analysis,the paper has made an investigation into the development status and problems of the agroecosystem in Urumqi.The result shows that:(1) in Urumqi,environment-energy of agro-ecosystem which mainly includes water resource is more than that of others.Renewable organic-energy has low percent.Comprising with other agro-ecosystem in arid and sub-arid region,energy self-sufficiency ratio and energy per area have comparative advantage while renewable organic-energy /total of energy and energy devotion ratio have comparative disadvantage.So,the structure of energy input should be optimized;(2) the majority of energy output is livestock energy.System production has distinctive predominance degree,but economic productivity of farmers should be strengthened;coupling degree of system must be strengthened,too.System yields structure should be adjusted in order to promote the inversion among the agroecosystem productivities.(3) Through total compare,outskirts agro-ecosystem has lower energy devotion,higher energy yields and stronger sustainable development capacity.In order to boost up yields capacity and fundamental status of agriculture,outskirts agro-ecosystem should be developed in arid and sub-arid region.Relativing to other kind of agriculture,outskirts agro-ecosystem has great comparative superiority and developing potential,could yield both great productive value and and ecological service value,also act as shelter and protecting function to the cities in arid and sub-arid region.