Soil Colors - 5 Soil Samples Embedded in Plastic

Soil Colors - 5 Soil Samples Embedded in Plastic for Classroom Demonstrations

In a transparent plastic block, five natural dried soil samples (in vials) are embedded. They let you see how soils can vary in color (e.g., soils considered red soils), from gray through rusty to cinnamon hues. They also explain why color is one of the key features used for soil classification and assessment.

1 – Red soil, example I

2 – Chernozem (calcium-rich)

3 – Red soil with minimum humus content, example II

4 – Laterite

5 – Regosol

Block is wrapped in bubble wrap and placed in a closed cardboard box. Dimensions of the teaching aid: 14 x 6.5 x 1.8 cm.

What you should know!

Soil color is an important indicator of its properties and chemical composition. It is influenced by minerals, organic matter content, moisture conditions and drainage. Below are representative, basic soil colors and what they indicate:

• Black and dark brown soils: rich in organic matter such as humus. They are usually very fertile, retain water and nutrients well, making them ideal for cultivation.
• Red and yellow soils: their color comes from iron oxides (red from hematite, yellow from goethite). They indicate good aeration and drainage, but often have low nutrient content.
• Gray, blueish and greenish soils: usually poorly permeable, with a high groundwater level. Gray color indicates oxygen deficiency and the presence of reduced compounds, which can limit plant growth.
• White and light soils: may contain a lot of silica, lime or gypsum. They are often leached, poor in nutrients and organic matter.

Soil color helps farmers and soil scientists assess its physical and chemical properties and suitability for growing different crops, and indicates pedogenic processes taking place in a given environment.