关键词: 嫩江, 农业布局, 自然带, 黑土地带, 自然地带, 暗栗钙土, 草甸草原, 黑钙土, 湿润系数, 杂类草

Abstract: Nenjiang area is located in western Heilongjiong province. According to compre-hensive physical regionalization of China (1959). this area is wholly delimited tem-perate subhumid region and meadow steppe-black earth zone. Yet, according to our own field investigation in 1977-1978, two natural regions and three natural zone have been identified.Firstly, based upon temperature and moisture condition, the area may be divided into temperate sub-humid and temperate semi-arid natural regions, secondly based upon vegetation-soil criteria, temperate sub-humid region may be sub-divided into two natural zones: forest-steppe-black earth zone and meadow-steppe-chernozem, zone; and temperate semi-arid region contains only one natural zone-steppe-chestnut soil zone.In regard to agricultural development, forest-steppe-black earth zone should be devoted mainly to agriculture, secondly to forestry and thirdly to pasture; meadow-steppe-chernozem zone mainly to agriculture, secondly to pasture and thirdly to forestry; while steppe-chestnut soil zone mainly to pasture, partly to agriculture and forestry.