农田当量的涵义及其所揭示的我国土地资源的食物生产潜力——一个土地资源的食物生产能力评价的新量纲及其在我国的应用

农田当量是把单位面积标准传统农田一年一熟种植水稻的食物产出作为标尺,来衡量一切农用土地相对食物生产潜势的计量单位。它是适于衡量草地农业系统的评价土地资源食物生产能力的新量纲。本研究在界定了农田当量内涵的基础上,指出ALEU是运营模式(m)和核算尺度(T)的函数,是食物当量的“面积”表述,农田当量可以评价任何农业系统的食物生产潜力。对我国现行农业运营模式下的食物生产能力进行了实证分析,结果表明,我国现存农用土地的食物生产能力仅利用了生产潜力的43.59%,还有巨大的食物生产潜力有待开发。以此为依据对我国农业进行结构性调整,将现有耕地的20%实行草田轮作,以全国现有可用草地的3%建立丰产栽培草地,对全国草地农业的食物资源潜力做出估算,其食物生产潜力相当于新增0.52亿hm2农田当量,全国实行草地农业系统,其食物生产能力将是现行系统的1.23倍。

Arable land equivalent unit and potential food productivity of land resources in China

The arable land equivalent unit(ALEU) is proposed for evaluating the potential food productivity of agricultural land in China based on the annual rice production in monoculture.The ALEU is the function of the management model(m) and the scale of time(T) of the agricultural land utilizations.It could be used to measure food productivity for both arable and non-arable land which are used for food production.An empirical study was conducted to evaluate the food productivity under current farming systems in China.The results indicated that the total yield of food produced is only 43.59% of the land potential productivity.Based on this study a structural reform for Chinese agriculture was proposed.It is suggested that agro-grassland system should be developed in the country.The system will include the following main components: in the traditional cropping areas,instead of cereal monoculture,about 20% of the total arable land area should be used for cereal-forage rotation.In the pastoral areas,high productivity sown pastures should be developed and the area at least should reach 3% of the total rangeland areas in China.Compared to the current farming system the total food productivity of the proposed system could be increased by 23% which is equivalent to increase 52 million hectare ALEU.