中国农业生态经济系统能值利用现状及其演变态势

Evolutionary tendency & current status of Chinese agricultural economic ecosystem

20世纪80年代改革开放以来,中国农业生态经济系统农业资源的投入、产出以及进出口结构产生了巨大的改变。当前中国农业生态经济系统化肥、农药、机械等工业辅助能的能值投入已占了农业生产能值总投入的70%以上,以致耕地退化、农田生态系统恶化形势加剧;畜禽、水产养殖已在农业产业结构中占主导地位。在农产品进出口方面,已由最初的农产品能值净出口国转变为净进口国,农产品年能值消费量的5.5%需从国外进口,对国际市场依赖性加大;出口农产品能值占国内农产品产出能值总量的2%,畜禽产品、水产品出口成为核心农产品出口物资,为供应世界农产品市场做出了卓越的贡献,但规模化养殖引起的环境污染却日趋严重。尽管20多年来农业产业结构更为合理、农业生产水平大大提高,但13亿人口对农产品巨大的需求量仍使中国农业生态经济系统可持续发展面临严峻压力。

As the largest country in the world in agricultural products yield,requirement and consumption,China exerts a deep influence on world＇s environments and the international markets for agricultural products.The yield structures,inputs,imports and exports of.China agricultural economic ecosystem have changed greatly since 1980s＇.The inputs of industry products based on emergy such as fertilizer,pesticide and machine take more than 70 percent in total agricultural inputs emergy.Livestock,poultry and aquatic products are dominant in present agriculture;some of them are contributed to international markets,but bring out escalating pollution.The data proved that 5.5 percent of China domestic agriculture products consumption emergy relies on import,and 2.0 percent of agricultural yield emergy for export.Although the structure of agriculture has changed more reasonable,the productivity has improved greatly,China agriculture ecosystem is still under tremendous pressure that is brought by the great consumption requirements with the population of 1.3 billion.