一、土壤普查的目的和任务土壤普查实际上就是大比例尺土壤调查制图(包括土壤详测制图)。国际上通常采用比例尺1∶10000至1∶25000的航片或实测地形图为底图,而在特殊农区或试验区则多采用1∶500,1∶2000或1∶5000比例尺的底图。在一些国土比较小的国家(如朝鲜、罗马尼亚、日本),几乎每隔几年 First, the purpose and mission of soil census Soil census is actually a large-scale soil survey mapping (including detailed soil mapping). In the world, aerial photos or measured topographic maps with scale 1: 10000 to 1: 25000 are usually used as base maps, while in agricultural or pilot areas, base maps of 1: 500, 1: 2000 or 1: 5000 scales are often used. In some relatively small countries (such as North Korea, Romania, Japan), almost every few years