Soil color is an indicator of its chemical composition and a very good sign to determine its fertility.
Dark soils reflect a high nutrient content. They are ideal for almost all crops and their value increases accordingly to their depth.
Soil fertility decreases from black to brown, rust brown, red, gray, yellow. Chalky soils are less fertile and are not recommended for agriculture.
Also, black soils absorb more solar radiation during the day and release more heat at night, leading to the formation of “underground dew”, a phenomenon particularly favorable for the plant.
Interesting facts about soils
The color appearance of soil layers provides more information about how plants “feel” in them. For example:
Marbling-mosaic soil layers color suggests temporary excess water or fluctuating aquifers.
Bluish-green or olive color indicates the presence of ferrous compounds formed in the absence of oxygen, which makes that soil type unsuitable for plants.
The existence of bright color halos around the roots indicates an excessive soil watering, which usually leave the plants drowned.
Image Credits: The Growing Club