The biochar used on agricultural land, can have a wide range of physical, chemical and biological effects on soil properties. Also cattle manure is important not only as the amount of nutrients inserted into the soil, but also for improving the conditions for growth and development of the plants. The positive effects on soil properties and plant growth are usually observed when biochar is used in mixture with other types of organic fertilizers. In this study, was used sewage sludge biochar, cattle manure compost, and mixtures made from these organic wastes in different concentrations, at application rates of 5 t/ha and 30 t/ha, with the aim of to determine the effects on soil properties and barley plants. The use of biochar, compost and biochar-compost mixtures at 30 t/ha, produced a significant increase of barley plants and an improvement of the pH, electrical conductivity and soil respiration, while at 5 t/ha application rate, the effect of this two organic wastes and mixtures of these in different concentrations, on plants growth and soil was reduced.