Granular inorganic foam particles made from recycled glass absorb water and can improve water retention in arid irrigated soils used for agricultural crops. This will reduce the amount of and/or frequency of irrigation water demand. Currently there are vast areas of agricultural land that rely on irrigation to be productive due to low water retention of the natural soils and high evaporation. This water insoluble material, which is a byproduct of our current process and could be mass-produced efficiently, absorbs water through capillary action and will release it to the plant roots as the surrounding soil moisture drops. Heated to the softening temperature, this material is sterilized in the manufacturing process and will not be degraded by soil microbes but will act as a substrate for them. Beneficial microbes or nutrients could be applied to the interstitial spaces prior to cropland application providing a carrier for other materials. Recycled glass is inexpensive and available broadly. Using it in this application will improve the soil, lower water usage and pumping cost, and reduce landfill volume.