Moisture that is left in the soil, along with hygroscopic moisture and water vapour, after the gravitational water has drained off. Capillary moisture is held by surface tension (known in the US as ‘water potential’) as a film of moisture on the surface of soil particles and peds, and as minute bodies of water filling part of the pore space between particles. Curved water surfaces or menisci (singular: meniscus) form bridges across the pores at the boundaries between their water-filled and air-filled parts. Capillary moisture may move through the soil under the influence of surface-tension forces (see capillary action) and some of it may be used by plants.
Subjects: Ecology and Conservation — Earth Sciences and Geography.