soil order system

Pedology is the scientific study of soils, encompassing their physical and chemical properties, the role of organisms, and their formation and mapping. The U.S. Soil Taxonomy is a system that classifies soils into 12 orders based on diagnostic horizons, which are distinct soil layers used for classification. For example, Alfisols are arable soils typically found under deciduous forests, characterized by horizons enriched in clay. Aridisols, on the other hand, are dry desert soils with low organic content and are found in arid regions. These classification systems, like the U.S. Soil Taxonomy and the FAO's World Reference Base for Soil Resources, use structural properties and soil-forming factors to categorize soils. Soils are studied as pedons, the smallest unit of landscape, which are grouped into polypedons for taxonomic classification.123456