Question

In addition to the rock particles, the soil contains
(a) Air and water
(b) Water and plants
(c) Minerals, organic matter, air and water
(d) Water, air, and plants

Answer 1

Hint: Soil composition refers to the minerals found in the soil and various other substances. Soil is a significant source of nutrients plants need for growth. Nitrogen (N) , phosphorus (P) , and potassium (K) are the three primary nutrients. They form the trio together known as NPK.

Complete answer:
Minerals, organic matter, water, and air are the essential constituents of soil. The standard soil is made up of about 45 percent mineral, 5 percent organic matter, 20-30 percent water, and 20- 30% air.
In the combined state minerals such as iron and aluminum are present. Like Bacteria and Plants, organic matter is also present. Depending on the inter- soil area, there is air present. Depending upon the water- retaining ability of the soil, the soil would be certainly present in the soil.
Additional information:
Calcium, magnesium, and sulfur are also essential nutrients. Plants also require small amounts of iron, manganese, zinc, copper, boron, and molybdenum, known as trace elements since the plant only requires traces.
Organic matter plays two primary purposes as a revolving fund for nutrients. They are
- Since soil organic matter is primarily derived from plant residues, it contains all the important plant nutrients. Hence stored organic matter is a plant nutrient storehouse.
- The stable organic fraction (humus) adsorbs in a plant- available form and retains nutrients.
So, the correct answer is, 'Minerals, organic matter, air, and water'.


Note: Organic matter remaining as raw plant residues on the soil surface helps protect the soil from the effects of drought, wind, and sunlight. Removal, incorporation, or burning of residues exposes soil to adverse climatic effects, and removal or burning deprives soil species of their primary source of energy.