Calculation method for water-saving irrigation design irrigation quota of fruit tree

The invention discloses a calculation method for a water-saving irrigation design irrigation quota of a fruit tree. The method comprises the following steps: 1, taking a single fruit tree as an irrigation design object; 2, calculating the volume S*H of a soil wetting body in a planned wetting area of a fruit tree root area, wherein S is the horizontal projection area of the soil wetting body in the planned wetting area of the fruit tree root area, and H is the planned wetting layer depth of the fruit tree root area; 3, calculating the increment of the designed soil volume water retention rate;and 4, calculating the designed irrigation quota of the fruit tree. For dispersedly planted plants or crops such as fruit trees, the size of the irrigation wetting range is determined according to the size and growth vigor of a single fruit tree and is not limited by the planting density and number of the fruit trees, the irrigation amount is closer to the actual requirement, and the influence ofunreasonable wetting rati