jordvätskespänningen

Jordvätskespänningen, often translated as soil moisture tension or soil matric potential, is a measure of the energy with which water is held within the soil pores. It quantifies how tightly soil particles bind water, making it more or less available to plants. Essentially, it describes the "pull" of the soil on the water.

This tension is a critical factor in understanding plant water uptake. When soil moisture tension is low, meaning water is loosely held, it is readily available for plants to absorb. As plants transpire or water evaporates from the soil surface, the soil dries out, and the water molecules are held more tightly. This increases the soil moisture tension.

Measurement of soil moisture tension is typically done using tensiometers. These devices consist of a porous ceramic cup filled with water, connected to a vacuum gauge. As the soil dries, water is drawn out of the cup into the soil, creating a vacuum that is registered by the gauge. Different soil types exhibit different soil moisture tension characteristics due to variations in pore size distribution and particle surface area. Sandy soils, with larger pores, generally have lower moisture tension at a given water content compared to clay soils, which have smaller pores and a higher surface area. This has significant implications for irrigation scheduling and agricultural practices.