Red Soil Field near Kulen Mountain-planting cassava field on red soil

Red soil contains a high percentage of iron content, which is responsible for its color. This soil is deficient in nitrogen, humus, phosphoric acid, magnesium, and lime but fairly rich in potash, with its pH ranging from neutral to acidic.

Red soil is a type of soil that typically develops in warm, temperate, and humid climates and comprise approximately 13% of Earth's soils. It contains thin organic and organic-mineral layers of highly leached soil resting on a red layer of alluvium. Red soils contain large amounts of clay and are generally derived from the weathering of ancient crystalline and metamorphic rock. They are named after their rich red color, which can vary from reddish brown to reddish yellow as a result of their high iron content. Red soil can be good or poor growing soil depending on how it is managed. It is usually low in nutrients and humus and can be difficult to cultivate due to its low water holding capacity; however, the fertility of these soils can be optimized with liming and other farming techniques.

Red soils are an important resource because they make up such a large portion of farmland on the earth. In countries such as China, India, and Greece where there are large amounts of red soil, understanding the soil's properties are crucial to successful agriculture. Red soil properties can vary across regions and may require different management practices to achieve the best results.