available water		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".
deep drainage		Water that moves so deep into the soil than crop roots can not extend deep enough to extract it; deep drainage ultimately becomes groundwater recharge. In this project, 1.6 m is taken to be the depth beyond which most crops' roots do not pass, and at which deep drainage is measured.
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".
lower limit		The water content at which the soil is so dry that plants can not extract any more water from it
water content		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.]