PURPOSE:Title foam composition having a high density and high strength, which is useful as a soil conditioner, prepared by adding an inorganic filler to a urea/formaldehyde resin and forming the resulting mixture into particles. CONSTITUTION:To an aqueous solution of a urea/formaldehyde precondensate prepared by reacting urea with formalin there is added an inorganic filler, such as calcium carbonate or diatomaceous earth, so as to provide an apparent volume ratio of the filler to the urea/formaldehyde resin foam composition, of at most 90%, pref., 1-50%. The resulting mixture is mixed with an aqueous solution containing both a curing agent, such as phosphoric acid or sulfuric acid, and a foaming agent, such as an alkylarylsulfonate or a higher alcohol sulfate ester, and the final mixture is foamed and cured, and then pulverized into particles having a particle size of below 30mm, pref., 1-15mm.
