Matricpotentiaal

Matricpotentiaal is the component of the water potential in soil water that arises from capillary and adsorptive forces between water and soil solids. It represents the suction experienced by water as it moves through the soil and is typically negative in unsaturated soils, becoming zero when the soil is fully saturated.

In soil physics, the total water potential Ψ is the sum of several components: matric potential Ψm, osmotic potential Ψo, pressure potential Ψp, and gravitational potential Ψg. The matric potential, caused by the soil's texture, structure, and moisture state, is often the dominant component in the unsaturated zone and governs how water is retained and transmitted through the soil.

Matricpotentiaal is closely linked to the soil moisture retention curve, which relates water content to matric potential. As soils dry, Ψm becomes more negative, reflecting stronger capillary and adsorptive forces. Typical ranges include near 0 kPa at saturation, about −10 to −30 kPa at field capacity for many soils, and around −1.5 MPa (−1500 kPa) at the permanent wilting point. At very dry conditions, Ψm can reach several MPa of suction.

Measurement and application: matricpotentiaal can be assessed with devices such as tensiometers (for near-saturation to moderate dryness), pressure plates, or psychrometers for drier or saline conditions when osmotic effects are significant. Understanding Ψm is essential for predicting water movement, plant-available water, irrigation scheduling, and soil management, especially under varying textures, structures, and salinity levels.