The most fertile soil in the world is found in the Nile River and is called black soil. This soil is suitable for growing vegetables and grains.

The blacker the soil, the more organic matter and humus it contains. If the amount of humus in the soil is 10% or more, the color of the soil will be pitch black, and if it is 8-10%, it will be dark or dark brown. As a result of the decrease in the amount of humus, the color of the soil changes to dark gray, gray, light gray, and when it is too low, it has a liquid color. Soil fertility increases when it is properly cultivated, and on the contrary, it decreases due to improper cultivation. Depending on the level of humidity, the soil layer is wet, dry, moist, moist or dry. If water droplets seep between the soil layer, it is considered wet soil. When the soil is compacted, it is called loose soil if water drips from it.