Question

Red soil contains _____________ and hence it is red in colour.
A.Iron oxide
B.Carbon dioxide
C.Nitrogen
D.None of the above

Answer 1

Hint:Red soil is a type of soil usually found in the tropical and deciduous forests of the world. It is found in the areas that develop organic mineral layers under warm yet moist weather. The top part of the soil is in yellowish brown colour due to the presence of nutrients mixed with the decaying debris of fallen leaves. The colour of red soil can vary from red to brown, chocolate, yellow, grey, or sometimes even black. The colours vary when the concentration of metal ores change.

Complete answer:Red soils are a common soil type present in regions surrounding the equator and they are formed from iron-rich sedimentary rock. It is a bare soil type which contains a very small amount of nutrients on the top part but has fertile parts below that. It is not suitable for agriculture purposes but in tropical areas they provide nutrients alongside the nutrients from the fallen debris for the trees to grow forest grounds and deciduous forests. Red soil contains a high percentage of iron content, which is responsible for its colour. Even though the soil has a high amount of Iron oxide, it has very low levels of nitrogen and other elements and its pH ranges from neutral to acidic. Red soils are found in South America, Central Africa, South and Southeast Asia, China, India, Japan and Australia.
In India, red soil is categorised into two types, red loam soil and sandy red soil. Red loam soil is created when huge granite rocks undergo decomposition. This type of soil is found in the regions of Karnataka, Tamil Nadu, Odisha, Uttar Pradesh etc. Sandy red soil is formed when the granite rocks undergo disintegration. They are also found in the same regions where red loam soil is present.

Hence, the correct answer is option (A).

Note:To improve the fertility of red soils lime and fertilizers are added in adequate amounts in regions where agriculture is lifestyle. Furthermore, cultural practises such as adequate crop rotation, improvement of the quality of organic matter, the use of nutrient-efficient or acid-tolerant plant species or cultivars, and soil erosion control will optimise the efficiency of nutrient use and improve the yield of crops on these soils. In China, farmers' use of red soil for crop production depends not only on the use of such methods, but also on socio-economic factors and the availability of adequate incentives.