Test: Soil - UPSC MCQ

Weathering of rock takes place by action of wind, water and Glacier. Earthquake is not the natural force causing weathering.

The soils that contain particles of size less than 0.002mm are called clayey soil. It is most suitable for rice, wheat and gram.

Alluvial soil is also called as Khadar in some part of India.

Coffee cultivation is best suited in laterite soil. Laterite soil is found in Assam and Kashmir valley.

The different layers of soil are together called soil profile. Soil profile has different layers having different sized particles.

Alluvial soil is found in planes of north India that includes Bihar, Uttar Pradesh, Orissa and some part of Jharkhand.

The correct answer is D as ertisol clays are black when wet and become iron hard when dry. When drying, Vertisols crack and the cracks widen and deepen as the soil dries ; this produces cracks 2-3 cm wide. These are productive soils.

The removal of top layer of soil due to action of air, water or human intervention is called soil erosion.

Cotton is grown in Sandy loam soil that have good drainage system to support growth of cotton.

Plastics should be banned because plastic is non-biodegradable that causes soil pollution.

Dead and decaying materials produced by plants in the soil is called humus. Humus provides nutrients and increase water holding capacity of soil.

Explanation:

1. Laterite soils are generally red in color due to the presence of iron oxides. This statement is correct.

2. Laterite soils are not rich in nitrogen and potash. In fact, they are poor in nitrogen, phosphorus, and potassium, which are essential nutrients for plant growth. This statement is incorrect.

3. Laterite soils are not well-developed in Rajasthan and UP. They are mainly found in regions with high rainfall, such as the Western Ghats, Eastern Ghats, and the northeastern states of India. This statement is incorrect.

4. Tapioca and cashew nuts grow well on laterite soils because these crops can tolerate the acidic nature of these soils and do not require high levels of nutrients. This statement is correct.
 

Black soil is also called as Regar in some part of India.

A soil profile is a vertical section through different layers of soil. Each layer has different texture, colour and chemical composition.

Humus, Human excreta and dead plants and animals are organic matter present in soil. On the other hand, phosphate is inorganic matter.

The series of layer of soil profile each having characteristic feature is called horizon of profile.

Earthworms are called farmers friends because they make hole in soil to increase water percolation in soil. They also release organic wastes.

Latosols are red or yellowish-red in colour throughout and they do not have distinct horizons like a podsol. The red colour comes from the iron oxides in the soil. They are deep soils, often 20-30 m deep whereas podsols are 1-2 m deep.

Different layer of soil having characteristic feature is called soil profile.