摘要
关于农业生态系统能流特征的研究很多,但关于植物篱农作系统能流特征的研究很少。在四川盆地雨养丘陵农区,2/3的耕地土壤侵蚀严重,为了控制土壤侵蚀和提高耕地生产力,该区域大量栽种了植物篱。该研究通过了解作物与植物篱之间的能流交付作用,通过系统能量投入水平提高与结构优化,建立环境友好的农作系统,最终实现坡地农业的可持续。通过两年田间小区试验,详细记录所有劳力投入、化肥投入、农药投入、农事管理活动以及落叶的数量并折算为标准能量单位。作物收获后所有生物产量的能量根据其各部分的转换值折算为标准能量。系统能流特征及效率通过统计分析完成。通过研究主要获得了以下3个结论:1)"作物-植物篱"系统产出能和输入能的数量和结构变化主要受植物篱子系统类型的影响。与大面积旱坡地传统农作物生产系统比较,植物篱农作系统能有效提高系统光能利用率、人工输入能效率,耕地单位面积总产出能也会增加,坡度越大,相对增幅亦越大;由于能极显著减少无机能施入量,这有利于降低化肥农药使用量,减少对环境的污染和破坏。2)"作物-果树类植物篱"系统输入能总量和有机能输入量大幅度增加,因此有利于优化输入能结构,促进坡地生态系统良性循环和集约高效农业发展。3)"作物-草本植物篱"系统人工辅助能的输入量大幅度下降,由于它所需投入能少,有机能耗和无机能耗均低,人工输入能效率很高而生物产量也较高,并且它们提高了与其间作的其它作物的能量产投比,因此提升了整个系统能量产投比率;由于保水固土的生态功能显著,使它能在四川广大山地、丘陵区退耕还林还草工程中发挥重要作用。
Aims Energy flow characteristics of alley cropping have been rarely studied, although alley cropping is common in Sichuan in order to control soil erosion and promote productivity. Our aims are to understand growth pattern and production mechanization of crops, determine effects of hedgerows on main crops in order to realize positive interactions, promote the level and structure of energy inputs, optimize and establish an environment-friendly fanning system and realize sustainable agriculture on hillsides.
Methods We recorded labor input, fertilizer, pesticides, fanning activities and leaf fall on the soil surface in trial plots for two years. After harvesting, we separated plant parts to determine economic yield and biological yield, calculated energy of the different parts according to a conversion ratio of energy and studied energy structure and energy efficiency of alley cropping by statistical analysis.
Important findings In comparison with the traditional agricultural system on hillsides, there were differences between hedgerows and crop in shape and spatial distribution of crown and roots, such that light, heat, water and soil were utilized continuously in time and in space, resulting in enhanced efficiency of light utilization, efficiency of input labor energy utilization and total output energy per unit area on steeper hillsides. Moreover, input of inorganic energy of alley cropping was reduced significantly and use of chemical fertilizer and pesticide could be reduced, resulting in environmental protection. Quantity and structure change of output and input energy of alley cropping was affected mainly by the type of hedgerow subsystem. Total energy input （ including orgarlic energy） of hedgerow system with fruit trees was increased, which was useful for improving input energy structure and ecosystem and enhancing intensive agricultural development. A hedgerow system of shrubs and herbs could reduce input labor energy, decreasing input energy and input energy consumption greatly and resulting in increased efficiency of input labor energy utilization and biomass and energy output/input ratio of the main crops. Alley cropping conserved water and soil, thereby playing an important role in agricultural reform in the vast mountainous and hilly area of Sichuan.
出处
《植物生态学报》
CAS
CSCD
北大核心
2007年第5期960-968,共9页
Chinese Journal of Plant Ecology
基金
国家973计划(2006CB100206)
PPI-PPIC成都办事处资助
