草地土壤次生盐渍化
Secondary salinization of grassland soil
地质土壤环境
Geological and soil environment
卵石砂土层地质结构
geological structure of gravel sand layer
土壤地质分类
Geological classification of soils
土壤地质环境
Soil geologic environment
geologic environment of the soil
土壤质地结构
soil texture and structure