||The difference between the measured water content at a particular depth and the soil's "lower limit" at that depth, multiplied by the thickness of the soil layer that this water content represents, and measured as mm of water. Also called "plant available water".
|available water capacity
||The maximum value of available water in a particular layer, defined as the difference between the "lower limit" and "drained upper limit", multiplied by the thickness of the soil layer and measured as mm of water Also called "plant available water capacity".
|drained upper limit
||The practical upper limit of wetness; a well-drained soil, would rarely spend more than a day or two wetter than this. Also called "field capacity".
||The water content at which the soil is so dry that plants can not extract any more water from it
||Stored water is calculated as the average water content of a soil layer multiplied by the thickness of that layer, resulting in an amount of water measured in mm. If all of a rainfall event was captured by the soil (ie no runoff, no evaporation and no plant water uptake), the stored water in the soil would increase by an amount equal to the rainfall in mm.
||In these websites, the water content is defined as the volume of water in a given volume of soil [Note: this is equivalent to a depth of water in a given depth of soil. A 400 mm deep layer of soil with a water content of 0.1 therefore has 40 mm of water in it.]