Six mixts. of brown coal ash, industrial sewage sludge and straw chaff or sawdust were prepd., stored for 7 months at 10-15 degrees C under air and studied for pH, dry mass and chem. compn. The mixts. showed high content of org. C and Ca. They contained also S, P, K, Mg and N. The contents of heavy metals (Cd, Cr, Cu, Pb, Ni) did not exceed the limits allowed by actual stands. The mixts. were recommended for enriching the soils with organic matter and nutrients for plants.