华北平原集约农区种植业生态经济系统的能值分析——以河北沧州为例

从能值的角度出发,以华北平原代表区域——河北省沧州地区2003年统计数据和调查数据为基础,对该地区种植业生态经济系统的能值投入和产出进行首次分析。结果显示:该地区不可更新的工业辅助能占总能值投入的78.5%,可更新的能值投入仅占21.4%(可更新环境资源8.79%、可更新有机12.68%),说明农业生产过渡依赖于外源不可更新辅助能的投入;此外,高系统太阳能值转换率、低净能值产出率和高环境负荷率的特点,表明该地区种植业的科技发展水平比较高,对环境的压力相当大。综合结果说明种植业系统对环境资源的过度利用必然会引起生态环境的破坏。基于此,提出华北平原集约农区种植业生态经济系统可持续发展对策:以优化施肥为基础,合理减少化肥投入为代表,适当降低工业辅助能投入;调整农业增产投入战略,努力解决该地区以水资源短缺为主的作物增产限制因子;改变农业生产中有机能值与无机能值的投入比例,降低系统环境负荷率。

Emergy analysis of planting economic ecosystem in intensive agricultural region of North China plain: A case study in Cangzhou of Hebei province

From the angle of emergy, taking North China Plain as the representation region, based on statistical data and survey data in Cangzhou, Hebei province in 2003, energy inputs and outputs of planting economic ecosystem are analyzed for the first time. The result shows: the unrenewable industrial assistance emergy occupying 78.5% and the renewable emergy only occupying 21.4% of the total devotion (renewable environmental resources occupying 8.79%, renewable organic occupying 12.68%) in this area, which indicates that the agricultural production excessively relies on the devotion of extraneous unrenewable assistance emergy. In addition, the characteristic is the high transformation rate of solar emergy, the low net emergy output rate and the high environmental loading rate, which indicates that the level of planting technology development is quite high and the pressure to the environment is quite high in this area. In conclusion, the excessive exploitation of free environmental resources will cause the destruction of the ecological environment. According to all of this, the continuable countermeasure for planting economic ecosystem is proposed for intensive agriculture in North China plain region: 1. Taking rational fertilization as the foundation, the devotion of fertilizer as the representation and industry assistance is suitably reduced; 2. Adjusting the strategy of the devotion of agricultural production, the shorted water resources as the focus of limit factor of increasing crops production is struggling solved in this area; 3. Transform the rate of organic emergy to purchased emergy in planting economic ecosystem to reduce the environmental loading.