Uptake of water by the root system is critical for plant functioning, as it balances aboveground water losses by transpiration and facilitates movement towards the roots of nutrients and other chemicals. The coupled processes in the soil-plant-atmosphere continuum are controlled at the plant, the cellular, or even molecular level (Kramer and Boyer 1995; Steudle and Peterson 1998). A basic understanding is needed of the process of root water uptake, combining soil physical and plant physiological perspectives in models of plant behaviour. This can be related to the water status in their environment to determine accurate plot-level soil water balances, evaluate plant adaptation to drought, and analyse below-ground competition in mixed vegetation systems. At the most basic level, the soil-plant-atmosphere continuum concept (Huber 1924; Gradmann 1928; Van den Honert 1948) assumes steady-state flow and constant resistance. Obviously this is an oversimplification (Kramer and Boyer 1995), but it serves to remind us of the interrelationships between the soil, plant, and atmospheric factors that have to be taken into account when determining plant water Status. Any analytical description, or model, of the soil water balance needs to consider many processes that act simultaneously across a number of different time and spatial scales.
Tahun publikasi
2000
Penulis
Fernandez E; Clothier B; van Noordwijk, M.
Bahasa
English
Kata kunci
water uptake, soil water content, plants, water budget, isotopes
