Wasserhaltevermögens

Wasserhaltevermögen describes the ability of a material to retain water against gravity. In soil science, it denotes the amount of water that a soil can hold in its pore spaces at given matric potentials, typically described by the soil moisture retention curve measured in the lab. The plant-available portion is often defined as the water held between field capacity (the moisture content after drainage by gravity) and the wilting point (the moisture content at which plants can no longer extract water). The difference between these two values is called the available water capacity.

Factors: soil texture and structure are primary controls: finer textures (clay, silt) and well-aggregated structure increase contact area and capillary forces, boosting water retention; organic matter enhances porosity and water storage; soil salinity and temperature also modify retention. Water-holding capacity decreases with compaction and drainage.

Measurement: common methods include gravimetric or volumetric determination of moisture content at specific matric potentials using pressure plates, suction tables, or modern sensors (tensiometers, time-domain reflectometry). In soils, retention curves show how water content changes with suction.

Applications and significance: high Wasserhaltevermögen supports drought tolerance, determines irrigation needs, influences soil microbiology and nutrient availability, and affects erosion and land restoration. In non-soil materials, the term describes the ability of a material (e.g., absorbent polymers, textiles, concretes) to retain water, impacting filtration, hydration, and durability.

See also: field capacity, wilting point, available water capacity, soil porosity.