Question

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

Answer 1

Hint: Plants are grown in the soil. Since plants require many micro and macronutrients in the form of minerals are present in the soil. When dead animals and plants remain in the soil constitutes organic matter.


Complete step by step answer:
Soil is mainly formed from large rock particles. Large rock particles on weathering and natural erosion form the soil.
Various components form the soil. These are water, air, organic matter, and Minerals. A typical soil where the plants can grow contains approximately 45% minerals, 5% organic matter, 20-30% air, and 20-30% water.
When the rock particles get converted into the soil, it forms minerals. The major minerals present in the soil are calcium, sulfur, iron, magnesium, potassium, etc. Since all the dead remains of plants and animals are buried into the soil, these form the organic matter of the soil. There are three types of organic matter in the soil: fresh plant and living residue, decomposing organic matter, and stable organic matter which is also known as humus.
There are water and air molecules in the soil, which is needed by the plants for their normal functioning. Depending upon the amount of water in the soil, we can predict the fertility of the soil.

So, the correct answer is an option (d)- Minerals, organic matter, air, and water.


Note: The humus is mainly composed of nitrogen, phosphorus, and sulfur that provides nutrients to the plants and helps in soil aggregation. The organic matter is estimated in factors like rainfall, moisture, soil aeration, and temperature.