浙江省德清县农田生态系统能量投入的优化  

Optimizing the external energy input into farmland ecosystems of Deqing County, Zhejiang Province

作　　者：叶旭君[1] 王兆骞[1] 

机构地区：[1]浙江大学华家池校区农业生态研究所,杭州310029

出　　处：《生态学报》2001年第12期2081-2088,共8页Acta Ecologica Sinica

基　　金：浙江省自然科学基金 ( 6 980 0 3)资助项目

摘　　要：在实地调察研究的基础上 ,分析了 1 984～ 1 994年浙江省德清县农田生态系统的能量投入和产出的动态变化趋势 ,根据农田生态系统的能量转化规律 ,建立了该县农田生态系统的能量投入产出模型 ,利用边际平衡理论和分析方法确定了该县农田生态系统的能量投入合理范围、最优投能量和最优投能结构。结果表明 ,德清县农田生态系统的平均单位面积能量投入和产出总量差异不大 ,但从其投能结构来看 ,差异却极其显著 ,表现为投入的有机能迅速减少 ,而投入的无机能大幅度增加。能量产投比虽有波动 ,但差异不甚明显。经优化确定 ,该县高产、中产和低产农田生态系统的能量投入合理范围分别为 4 9.80～ 2 91 .1 6× 1 0 9J/ hm2 、34 .85～ 2 2 1 .5 9× 1 0 9J/ hm2 和 1 9.6 2～ 1 4 4 .1 9× 1 0 9J/ hm2 ;最优投能量分别为1 6 6 .0 8× 1 0 9J/ hm2 、1 2 2 .83× 1 0 9J/ hm2 和 74 .0 8× 1 0 9J/ hm2 ;最优投能结构分别为 1 .90 1 9、3.71 88和 6 .6 2 2 5。表明为提高有限资源的利用效率 ,对该县不同类型的农田生态系统 。This paper seeks to discuss the methodology to optimize the external energy input into farmland ecosystems, with an aim to providing realistic guidance to agricultural production. Since the 1960s a large number of studies on energy use in farmland ecosystems have been carried out and it has been shown that energy productivity and efficiency appears to be closely linked to specific characteristics of the land. Experimental work further revealed the sigmoidal relationship between energy input and output under given production conditions, showing that system energy output is positively related to input up to a certain point, after which system energy output asymptotically approaches a plateau level. This sigmoidal relationship is analogous with the ecological Logistic function of the population growth curve under limited spatial and resource conditions. Hence, the Logistic function was utilized to plot the relationship between energy input and productivity in farmland ecosystems. Using collected data from a specific farmland ecosystem, it is possible to calculate the potential maximum energy output, K m, and the estimated coefficients, r and C, in the Logistic model. According to this model the theoretical energy output of the agroecosystem at any given energy input level could be calculated.The marginal energy productivity (MEP), the average energy productivity (AEP) and the elasticity of energy input (EEI) were utilized to characterize the energy use efficiency of agroecosystems. According to the characteristics of Logistic function, the dynamics of MEP, AEP and EEI in agroecosystems were thoroughly analyzed. It was concluded that the rational range of energy input may be calculated by setting EEI within the inequality 0≤1. In addition, it is theoretically possible to identify the optimum amount of energy input to the system where the optimal input represents the input that meets a balance between the output of the system and economic profit. The optimal input can be calculated from the principle of marginal eq

关 键 词：农田生态系统 能量投入产出模型 能量投入合理范围 最优投能量 最优投能结构 浙江 

分 类 号：S181[农业科学—农业基础科学]