Question

The red soil appears red due to the presence of ___________.
A. Potash
B. Iron
C. Phosphorous
D. Humus

Answer 1

Hint: Red soil is a type of soil that grows under deciduous or mixed forest in a humid, temperate, moist environment, with thin organic and organic-mineral layers overlaying a leached yellowish-brown layer lying on a red illuvium layer.

Complete answer:
In the red soil, iron oxide is responsible for the red pigment. Generally, red soil is derived from crystalline rock. They are typically poorly tended soils, low in nutrients and humus, and difficult to plant because of their low capacity to retain water.
The red soil texture ranges from sand to clay, the bulk of which is loam. Their other features include porous and friable structure, lack of lime, free carbonates and kankar, and small concentrations of soluble salts. Its chemical composition consists of 90.47 percent insoluble content, 3.61 percent iron, 2.92 percent aluminum, 1.01 percent organic matter, 0.70 percent magnesium, 0.56 percent lime, 0.30 percent carbon dioxide, 0.24 percent potash, 0.12 percent soda, 0.09 percent phosphorus, and 0.08 percent nitrogen.
In general, these soils are deficient in lime, magnesia, phosphates, phosphorus, hummus, and potash. Extreme leaching is a danger to these soils. They are weak, weak and gravelly, sandy, or stony and brittle, light-colored soils on the uplands, on which food crops such as bajra can be cultivated. But they are rich, dense, dark-colored fertile loam on the lower plains and valleys on which they can continue under irrigation.
So, the correct answer is Option B.

Note: These soils are less fertile and have thin layers. These soils are primarily found in Karnataka (districts of Shimoga, Chikmaglur and Hassan), Andhra Pradesh (districts of Rayalaseema), Telangana, Tamil Nadu East (districts of Tiruvannamalai and Cuddalore), Orissa, Jharkhand (districts of Chotanagpur), Uttar Pradesh (districts of Bundelkhand), Madhya Pradesh (districts of Balaghat and Chhindwara), Rajasthan (districts of Banswara, Bhilwara, Bundi, Chittaurgarh, Kota, and Ajmer), Meghalaya, Mizoram, and Ajmer.