The colour of the soil depends on the amount of humus in its composition. Due to the high amount of humus in the top layer of the soil, its colour is dark (gray and brown). The more humus there is in the soil, the darker the colour of the horizontals in it. Humus in the soil contains nutrients necessary for the growth of the plant. Humus is one of the main criteria for soil fertility, making up 85-90% of the soil’s organic matter. Humus is formed as a result of decomposition of organic remains of plants and animals in the soil. Proper cultivation of the soil, storage of plant remains in the soil during the crop harvesting plays an important role in the formation of the organic part. This also leads to the activation of microbiological processes in the soil.