A method to reduce the amount of irrigation water wherein the device (2) is made of combusted biomass in cylinder shape with a diameter of 4cm / 6cm / 8cm and is inserted in various depths (1) and in various sizes/lengths under the source of water irrigation (3) in proximity to a tree or plant, and in different numbers according to the season. The device (2) has ability to absorb and store irrigation water in high capacity, up to 300% higher than the surrounding soil ground, being a sustainable source to supply the roots of a tree or plant with water in areas which suffer from shortfall or rain, with poor type of soil and depletion of underground water reservoir. The device (2) absorbs water and makes the surrounding soil constantly moist and wet by allowing diffusion of water from the device (2).
