大沟流域营林试验区土壤图是采用土壤组合发生制图原则编制的。以土壤分类为基础，分布规律作依据，着重反映岷江上游半干旱河谷山地土壤形成过程、条件、基本特征，并林木对土壤条件要求为主体现土壤属性。参照1984年中国土壤分类系统，将大沟流域土壤划分为新积土、褐色土、棕壤、暗棕壤、亚高山草甸土5类。简要说明分布面积、类型特征、理化性质、农业利用等，为造林立地类型划分、树种选择、林种选择、林种布局以及小流域综合治理规划提供科学依据。

Based upon the soil mapping prinelples of soil genetle condslderation and conbination, the soil map was drawn up for basin Doagou, a experimental and example are to be planted. The map emphasizes on the forming process in the semiarid vally of upper reach of river Minjiang by the regularity of the classdication and distribution of the soil on the moutain area. The divided for the basin, referecing with the Soil Classification System on Genaral Soil Survey over All China (1984), are five gruops of soil —— entisol, cinnsmon soil, brown soil, dark brown soil and subalpine meadow. The soil-forming cases, as well as the main charcteristics influemcing forestry development, for each group of soils were showed on the map providing forest managers with scientific testmory on landscape regionization, tree selection, forest renovation and plantation and on multiple planning and construction on the drainage basin.