农业用地的空时积和空时利用指数

复种指数(全年农作物播种总面积与总耕地面积之比)虽然概念清楚,但代表意义不明确,人们难以根据复种指数的高低确切地比较土地利用的充分程度。作者认为,农业土地资源的完整内涵应是农业土地面积和一年中土地可供作物生长的生长期长度之积,而作物在农业生产中占用的土地资源量应是作物占用的土地面积和占用的生长期长度之积。因而提出用“土地空时积”和“土地空时利用指数”,作为农业土地资源量和土地利用程度的度量指标,并讨论了这两个术语的扩展应用问题。

The "Land's Product of Space and Time" and "Land's Space-time Use Index" in Agriculture

The multiple crop index (a radio of annual total eroping area to total area of cultivated land) is clear and definite in concept, but indefinite in sense. It is difficult to define the degree of the full use of land unequivocally. The authors hold that the integrated connotation of agricultural land resource should be the product of cultivated land area and the length of period when crop can grow, and the amount of the land resource which is used by croping should be the product of the used area and the used period by the croping. So the authors advance a term "Land's Product of Space and Time" and a term "Land's Space-time Use Index" to express the amount of land resource and the degree of the land use in agriculture respectively and discuss the expansion of use of the terms.