The sewage sludge was taken from a dairy located in Krasnystaw. The six experimental treatments, without organic fertilization – control, FYM, sewage sludge under liming and no liming conditions were established on brown soil. The dose of sewage sludge was comparable to the N dose applied with 35 t ha-1 FYM, i.e. 175 kg N ha-1 and it allowed to draw a direct comparison of both fertilizers. The sewage sludge contained higher concentrations of P, Ca, N and Na than farmyard manure. None of the heavy metals exceeded the maximum value in the sludge; therefore, it can be used for fertilization of the soil as well as higher plants. Sewage sludge should be treated as an organic matter. The application of sludge gave a higher crop of wheat, higher thousand grain weight and higher content of protein in grain comparing to the treatment without organic fertilization (control).