FIELD: soil development. SUBSTANCE: invention, in particular, relates to agents and compositions brought into or onto soil to improve its structure, increase its productivity, protect against erosion, and also to fix moving sands and restore vegetation on various-type soils. Method includes ozonolysis in organic solvent of tar-asphalt components of low-sulfur petroleums and naphtene-type bitumens with butadiene rubber or its oligomers' additives, evaporation of solvent, and addition of water-soluble calcium salt. Hydrolysis of ozonolysis products is conducted while simultaneously heating them with aqueous alkali solution, after which desired product is isolated from aqueous solution by distilling away water and drying salt mixture. In a preferred embodiment of invention, weight portion of butadiene rubber added to petroleum products constitutes 0.5 to 4% and calcium-to- alkali metal weight ratio ranges from 1:2.2 to 1:20. As alkali, potassium hydroxide is used and concentration of calcium in agent does not exceed 4%. EFFECT: increased soil-development activity, simplified preparation technology, and reduced cost. 5 cl, 12 ex
