Answer : (a) New Delhi Explanation: New Delhi, being located in the northern plains of India, experiences a continental climate with extreme temperatures. During the daytime, especially in the summer months, New Delhi records some of the highest temperatures in India, often exceeding 40°C (104°F). This is due to its geographical location and the influence of the Thar Desert in Rajasthan, which brings hot winds to the region. In contrast, Mumbai, Chennai, and Kolkata generally have milder temperatures due to their coastal locations and maritime climates.
Explanation: According to the Indian Council of Agricultural Research (ICAR), there are eight different types of soils found in India. These are: Alluvial Soil Black Soil (Regur) Red Soil Laterite Soil Mountain or Forest Soil Arid or Desert Soil Saline and Alkaline Soil Peaty and Organic Soil Top of Form
Answer: (a) Alluvial soils Explanation: Alluvial soils are formed by the deposition of sediments by rivers and are typically fertile and rich in nutrients. They are well-suited for the cultivation of cereals like rice, wheat, and maize due to their fertility, good drainage, and ability to retain moisture. Red soils are generally less fertile and more acidic, while laterite soils are poor in fertility and not suitable for cereals cultivation.
Answer: (b) Regur soil Explanation: Regur soil, also known as black soil or cotton soil, has the maximum water retention capacity among the options provided. This soil type is rich in clay minerals, which help it retain water well. Red soil, desert soil, and laterite soil are generally less effective in retaining water compared to regur soil.
Answer: (a) Wet tropical climate Explanation: Laterite soil is formed in hot and humid tropical areas with heavy rainfall. The high temperatures and abundant rainfall in these regions lead to intense weathering of the parent rock, resulting in the formation of laterite soil. This type of soil is typically rich in iron and aluminum oxides and is known for its poor fertility and ability to harden into a brick-like structure when dry.
Answer: (c) Due to the presence of iron Explanation: Red soils develop a reddish color due to the presence of iron oxide, especially hematite (Fe2O3). Iron oxide gives the soil its characteristic red coloration. Overgrazing does not directly cause the soil to become red. Potash and magnesia may contribute to the fertility of the soil but do not cause the red coloration.
Answer: C.1 and 4 Explanation: Laterite soils are generally red in color due to the presence of iron oxides. They are not generally rich in nitrogen and potash; instead, they are often deficient in these nutrients. Laterite soils are not well-developed in Rajasthan and UP; they are more commonly found in areas with high rainfall and high temperatures. Tapioca and cashew nuts are crops that grow well on laterite soils due to their ability to withstand drought conditions and thrive in nutrient-poor soils.
8.Salinization occurs when the irrigation water accumulated in the soil evaporates, leaving behind salts and minerals. What are the effects of salinization on the irrigated land? (UPSC- 2011)
Answer: B Explanation: Salinization can lead to the accumulation of salts in the soil, which can make the soil impermeable. This can hinder the movement of water and nutrients in the soil, negatively impacting plant growth
Answer: A .Alluvial Soil Explanation: Alluvial soil is the most widespread and important soil group in India. It is formed by the deposition of silt, clay, and sand carried by rivers and streams, making it fertile and suitable for agriculture.
Answer: (c) Sandy soil Explanation: Black soil, also known as regur soil, is characterized by its high clay content, which makes it very sticky when wet and hard when dry. This characteristic makes black soil challenging to cultivate, as it can become compacted easily, leading to poor aeration and drainage. Additionally, its high clay content can make it challenging for roots to penetrate, affecting plant growth.
Answer: Option 4 : Alluvial soil Explanation: Alluvial soil is found in most (43.4%) of the landmass in India.Other soils are found in black soil, red soil, and laterite soil. Alluvial Soil :It is the soil of the plains of North India and the coastal plains of South India, which is mainly carried by rivers.Potash and lime are found in abundance in this soil and lack of phosphorus, nitrogen, and bacteria.This soil is very fertile for the cultivation of sugarcane, wheat, paddy, oilseeds, pulses, etc.
Answer : Option D: Red soil Explanation: Red soils are formed mainly by alfisols soil order.Red soils are having high Phosphorus fixing capacity because of the presence of Kaolinite clay mineral.These soils are lightly textured with porous and friable structure and there is an absence of lime Kankar and free carbonates.This soil is also known as the omnibus group. The presence of ferric oxides makes the colour of soil red.They have neutral to acidic reaction and are deficient in nitrogen humus, phosphoric acid and lime. Crops suitable: wheat, cotton, pulses, tobacco, millets, orchards, potato and oilseeds.
Answer: Option A: Igneous rock Explanation: Igneous rock is also called is magmatic rock. By cooling and solidification of magma or lava Igneous rock is formed.Basalt and Granite are the best examples of Igneous rock.
Answer : Option A : Soil color Explanation: Munsell color system is used to determine Soil color.Munsell color system was invented by Professor Albert H. Munsell.Soil color is determined by the following three properties.HUE: Denotes dominant spectral color. (Yellow, red, brown, and blue)VALUE: Denotes the lightness and darkness of a color.CHROMA: Denotes purity of color.
Answer Option B : B Explanation: Alkali soils have pH > 8.5, a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5m to 1 m depth.Red soil is red in colour is due to the presence of iron oxide and are not calcareous. They are acidic mainly due to the nature of the parent rocks.Laterite soils are rich in bauxite or ferric oxides and pH of Laterite soil is 4.5-6.5.Black soil is rich in organic matter and montmorillonite which is responsible for its swelling and shrinking characteristics.Kaolinite is a clay mineral is the weathering product of feldspars.
Answer: (b) Black soil Explanation: Black soil is also known as Regur Soil.It occupies about 15% of area in India.It is mostly found in the Deccan plateau – In parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and some parts of Tamil Nadu.It is rich in many minerals like Iron, lime, calcium, potassium, aluminum, and magnesium and deficient in Nitrogen, phosphorus, and organic matterIt is the best soil for the cultivation of cotton.
Answer: Option D: Alluvial soil Explanation: Alluvial soil mostly available soil in India (about 43%) covers an area of 143 km2.It is widespread in northern plains and river valleys.In peninsular India, they are mostly found in deltas and estuaries.Humus, lime, and organic matters are present in this soil and highly fertile.It is found in Indus-Ganga-Brahmaputra plain, Narmada-Tapi plain, etc are examples.They are depositional soil – transported and deposited by rivers, streams, etc.New alluvium is termed as Khadar and old alluvium is termed as Bhangar.Its color is Light Grey to Ash Grey.Its texture is Sandy to silty loam or clay.Wheat, rice, maize, sugarcane, pulses, oilseed, etc are cultivated mainly in this soil.
Answer: (a) Pea Explanation: Pea is a leguminous crop that enriches the nitrogen content of the soil by forming a symbiotic relationship with nitrogen-fixing bacteria in its root nodules.
Answer: Option C: Fulvic acid Explanation: There are two major groups under Humus-i) Humic group, ii) Non-humic group.Under the humic group 5 sub-groupings are there-i) falvic acid, ii)humic acid, iii)humin, iv) apocremic acid, v) Hematomelanic acid.Molecular weight of falvic acid is the lowest and it is the lightest in colour among all.
Answer: (c) Terai Explanation :Types of alluvial soils: Bangar – Old alluvium, Deposited far from the flood plains of the rivers Khadar – New alluvium, Occupies the flood plains of the rivers
Answer: (b) Malwa plateau Explanation: Lava soil is formed from the solidification of volcanic lava and is typically found in regions with past or present volcanic activity, such as the Malwa plateau.
Answer: (a) Soil conservation Explanation: Contour bunding is a practice for soil conservation.It is a sustainable land management practice for sloping and hilly areas that involves the placement of lines of stones along the natural rises of a landscape.This technique helps to capture and hold rainfall for a longer period of time before it can become runoff.This practice inhibits wind erosion by keeping the soil moist and heavy.
Answer: (a) Malabar coastal region Explanation: Laterite soil is a type of soil rich in iron and aluminum found in hot, wet tropical areas like the Malabar coastal region
Answer: (c) Alluvial soil Explanation: Alluvial soil, found in river valleys and plains, is considered the most productive soil in India due to its high fertility.
Answer: (d) Mountain soil Mountain soil generally has an immature soil profile.It is mainly found in hilly and mountainous regions.The texture of the soil depends on the mountain environment where they are found.It is suitable for horticulture, tea, and crops like apples, potatoes etc.
Answer: (b) Black soil Explanation: Black soil is also known as Regur Soil.It has the highest water retaining capacity among all types of soils available in India.It swells and becomes sticky when wet.It shrinks and develops wide cracks when dried.
Answer: (a) Low rainfall Explanation: Red soil is mainly found in the areas of low-rainfall.It occupies about 18.5% of area in India.Its color is red due to the presence of Ferric oxide.It is deficient in lime, phosphate, manganese, nitrogen, humus, and potash.
Answer: (d) High temperature and High rainfall Explanation: Laterite soil is mainly found in the areas of high temperature and high rainfall.It occupies about 3.7% of area in India.It is mainly formed as a result of high leaching.Leaching occurs when excess water removes water-soluble nutrients out of the soil.It is deficient in Lime and silica(as they are leached away from the soil).
Answer: (c) All of the above Explanation: Peaty/Marshy soil is mainly found in the areas of heavy rainfall and high humidity where water tables are generally high.It is found in Kerala backwaters and parts of northeastern India.Growth of vegetation in this type of soil is very low.It contains a large quantity of dead organic matter/humus. It is suitable for cultivation of rice and aquatic crops.
31. Which of the following natural vegetation referring to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time?
Answer: B Explanation: Virgin vegetation refers to a plant community that has grown naturally without human aid and has been left undisturbed by humans for a long time. It represents the original vegetation of a region before it was altered or destroyed by human activities like agriculture, urbanization, or deforestation
Answer: C Explanation:Laterite soil is characterized by its formation due to intense leaching, which is the process of minerals being washed away by water, leaving behind a residue rich in iron oxides and aluminum hydroxides. While laterite soils are rich in iron and aluminum, they are not typically fully equipped with organic matter, as this depends on the specific conditions and history of the soil.
Answer: D Explanation: The red color of red soil is primarily due to the presence of iron oxides, particularly hematite (Fe2O3) and goethite (FeO(OH)). These iron oxides give the soil its characteristic red or reddish-brown color. The iron oxides are formed through the weathering of rocks containing iron minerals, and their presence in the soil gives it fertility and good drainage characteristics
Answer: A Explanation: Black clay soil, also known as regur soil, is known for its ability to form deep cracks and shrink in dry conditions. This soil type is rich in nutrients and is highly suitable for agriculture, but its tendency to shrink and form cracks can pose challenges for farming activities.
Answer: B Explanation: Black cotton soil, also known as regur soil, is related to the term “Regur.” This soil is characterized by its high clay content and is known for its ability to retain moisture, making it suitable for crops like cotton. However, its high clay content also makes it prone to shrinking and swelling, which can affect farming activities.
Answer: D Explanation: Statement I: Correct Regur soils are also known as black cotton soils. They are formed by the solidification of lava spread over a large area of the Deccan plateau. The cooling and solidification of volcanic lava lead to the formation of these deep, dark, and clayey soils. Statement II: Correct Regur soils are rich in mineral content, particularly iron, magnesium, and aluminum. This richness is attributed to the volcanic activities that formed these soils. The volcanic ash and basaltic rock fragments in the soil contribute to its fertility. Statement III: Correct Regur soils are predominantly found in the Deccan plateau region, covering states like Karnataka, Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh, and Tamil Nadu. These soils are known for their high moisture retention capacity and ability to swell and shrink significantly with changes in moisture content.
Answer: A Explanation: Sandy soil has larger particles compared to clayey or loamy soil, which allows for more air space between particles. This makes sandy soil loosely packed and well-aerated, which is beneficial for plant root growth and drainage.
Answer: C Explanation: Chemical weathering involves the alteration of rock materials through chemical processes. Oxidation, where minerals in rocks react with oxygen, is an example of chemical weathering. Frost action and repeated wetting and drying are examples of physical weathering, not chemical weathering.
Answer: B Explanation: Mass movement refers to the downhill movement of soil and rock under the influence of gravity. Soil creep, a slow and continuous movement of soil downhill, and landslides, a rapid movement of a large mass of soil and rock, are examples of mass movement. Weathering, on the other hand, is the breakdown of rocks into smaller particles by physical, chemical, or biological processes
Alluvial soils cover about 40 percent of the total geographical area of India. They are formed by the deposition of fine silt, clay, and sand carried by rivers and streams over time.
Statement II: Correct
Alluvial soils are formed due to the depositional work done by rivers in plains, valleys, floodplains, and deltas. The sediments deposited by rivers over thousands of years create fertile alluvial soils, which support agriculture in these regions.
