Question

Which is the most fertile soil among the following?
(A) Black soil
(B) Red soil
(C) Laterite soil
(D) Alluvial soil

Answer 1

Hint:
 Soil fertility refers to the ability of the soil to sustain the growth of agricultural crops, e.g. The ability to supply essential nutrients and water in sufficient quantities and to maximize plant growth and fertility.

Complete step by step solution:
Soil reproduction is a complex process that involves the continuous cycling of species between living and non-living things. As plant material and animal waste are killed by microorganisms, they release inorganic nutrients into the soil solution, a process called mineralization. The nutrients can then undergo changes that may be facilitated or enabled by microorganisms. Like plants, many microorganisms need or use rare forms of nitrogen, phosphorus or potassium and will compete with plants for these nutrients, binding nutrients to microbial biomass, a process often called immobilization. The balance between dehydration and mineral processes depends on the balance and availability of large amounts of nutrients and living carbon in microbes. Natural processes such as lightning strikes can fix atmospheric nitrogen by converting it to (NO2). Denitrification can occur under anaerobic conditions (floods) where there are invasive bacteria. This is the most widespread and important type of soil. In fact, all the Northern Plains are made up of all the earth. Composite soils have different concentrations of sand, mud and clay. The fertile soil is very fertile. Mostly this soil contains a sufficient amount of potash, phosphoric acid and lime.

Hence, the correct answer is option D.

Note:
 Lands used for agriculture and other human activities, care for soil fertility requires the use of soil conservation practices. This is because soil erosion and other forms of soil degradation often result in a decline in quality in relation to one or more of the factors listed above.