Question

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

Answer 1

Hint:The color shown by any soil is due to the nutrients which are present in that soil. The one main factor that determines the color of the soil is the composition of oxides of which the soil is designed.

Complete answer:The color of red soil may vary from a variety of colors namely from red to brown, yellow, gray, or even black in some cases. Red soil contains a fairly high percentage of iron content, which is the reason for its color since iron oxide is reddish-brown in color. Red soil is deficient in common nutrients like nitrogen, humus, phosphoric acid, lime, magnesium, etc. but it is fairly rich in potash, and the pH of the soil ranges from neutral to acidic. Its formation occurs due to the weathering of ancient crystalline and metamorphic rocks generally acid granites, quartz rocks, gneiss, and felspathic rocks. If we look at the chemical composition, red soil is basically siliceous and aluminous, along with free quartz present as sand, but it is rich in potassium. Red soil may range from sand to clay with the majority of it being loamy. The lowermost area of red soil is dark-colored and very fertile, whereas the upper layer is relatively sandy and porous. Thus, with the proper use of fertilizers and irrigation one can yield a high production of various crops namely cotton, millets, wheat, rice, oilseeds, pulses, tobacco, and fruits.

Thus, the correct answer is B.

Note:Red soil is a very important soil resource, bearing a substantial implication for the sustainable development of agriculture and the healthy growth of the economy.