Soil shrinking and swelling with water, leading to crack formation, is the primary abiotic soil structure forming process. Shrinking is mostly due to the soil colloids forming the soil plasma, which produces a characteristic shrinkage curve (SC) on drying. Soil shrinkage has physical, geotechnical and pedological applications with relevance to (i) its impact on soil hydrodynamics (preferential flow in cracks and changes in the hydraulic characteristics) and (ii) improved impact diagnosis and upscaling of physical properties by deterministic SC modeling. In natural soils, organic matter and aggregation affect shrinkage and therefore the development of soil structure by drying and wetting.