Chapter-9 Soil

Explanation:

Loamy soil provides an ideal balance of different soil characteristics. Loamy soil is a mixture of sand, silt, and clay particles with a good amount of organic matter, which gives it excellent drainage, moisture retention, and nutrient-holding capacity.

Explanation:

Rock particles and humus together make a mixture known as soil. There are many different types of soils, each with its unique characteristics, including texture, structure, color, pH, and nutrient content.

Explanation:

The type of soil that is most well-aerated is sandy soil. Sandy soil has a larger particle size than other soil types, which creates larger air spaces between the particles. Thus, the air can move freely, making it well-aerated soil.  

Explanation:

Sandy soil typically has the highest percolation rate among soil types. Sandy soil has large particles and a porous structure, which allows water to move quickly through the soil and drain away. This is due to the large air spaces between the sand particles, which creates much space for water to flow through.

Explanation:

Clay soil has the least percolation rate among soil types. Clay soil has small particles and a tightly packed structure, meaning the water has less space to flow through. This can cause water to pool on the surface or lead to waterlogging in the soil, which can harm plant growth.

Explanation:

Humus is the dark, organic material that forms in the soil due to the decomposition of dead plant and animal matter. It is a key component of healthy soil, as it provides a source of nutrients for plants and helps to improve soil structure and fertility.

Explanation:

Humus is found in the topsoil layer or A-horizon of the soil. The A-horizon is the uppermost layer of the soil profile and is typically where the majority of the organic matter in the soil is located. The presence of humus in the soil is important for soil fertility, as it contributes to soil structure, nutrient cycling, and water retention.

Explanation:

A lesser amount of humus but more minerals is the B-horizon or subsoil layer. The B-horizon is located beneath the A-horizon and is typically composed of mineral particles weathered and transported from the layers above. While there may be some organic matter in the B-horizon, it is generally less than what is found in the A-horizon. The B-horizon often contains a greater concentration of minerals such as clay, iron, aluminum, and calcium, which have been leached down from the A-horizon over time.

Explanation:

Clayey soil is the preferred type for making various crafts and objects due to its unique properties and versatility. Clay soil is a type of soil that is composed of fine-grained minerals and has a high proportion of clay particles. This soil type is known for its plasticity, making it easy to mold and shape. Clay soil is also very durable and has good water retention properties, which helps to keep objects made from it intact over time.

Explanation:

The type of soil best for making these types of containers is a mixture of clay and sand. The clay provides the necessary plasticity and binding properties, while the sand helps improve the soil's porosity and prevent cracking during the drying and firing process.

Explanation:

Because it contains a high amount of organic matter, such as decomposing plant material, and humus, which is the dark, organic component of soil. The organic matter in the A-horizon is rich in nutrients, such as nitrogen and phosphorus, which are essential for plant growth, and it also helps to retain moisture in the soil.

Explanation:

The role of humus in a soil is crucial for maintaining soil health and supporting plant growth. Humus is a source of plant nutrients, and it helps release nutrients such as nitrogen, phosphorus, and potassium into the soil. Humus can absorb and retain water, which helps to maintain soil moisture levels and prevent waterlogging. 

Explanation:

Soil profile refers to the vertical arrangement of soil layers, or horizons, in soil. A soil profile consists of several horizons, each of which has distinct physical and chemical properties that are influenced by climate, vegetation, and geological processes. The different soil horizons are identified based on their color, texture, depth, and other characteristics, and they are labeled with letter designations that indicate their position in the soil profile.

Explanation:

Loamy soil is a type of soil that is characterized by a balanced mixture of sand, silt, and clay particles, as well as a high percentage of organic matter. Loamy soil is considered one of the best soil types for plant growth because it has a balance of different particle sizes that allows for good drainage, moisture retention, and nutrient availability.

Explanation:

It is found just below the C- horizon. Bedrock is the solid rock that underlies the soil, sediment, and other unconsolidated materials on Earth's surface. The solid, unbroken layer of rock forms the foundation of the Earth's crust.

Explanation:

Loamy soil is the most suitable for growing wheat and gram. It is a balanced mixture of sand, silt, and clay particles with a high percentage of organic matter. Loamy soil provides good drainage, moisture retention, aeration, and nutrient availability, which are essential for the growth of wheat and gram crops.

Explanation:

Areas with arid and semi-arid climates tend to be more prone to severe soil erosion due to their low vegetation cover, high wind velocity, and sporadic rainfall, which can result in the removal of the topsoil layer. This can lead to desertification and reduced soil productivity, significantly impacting local communities and economies.

Explanation:

Lentils grow best in soil that is rich in nitrogen, phosphorus, and potassium, which are essential nutrients for their growth and development. Loamy soil with a high organic matter content supports the growth of beneficial microorganisms that help to decompose organic matter and release these nutrients into the soil.

Explanation:

Cotton is a crop that grows best in well-drained, fertile soil with good moisture retention and a pH range of 6.0 to 7.0, and loamy soil does the work. Loamy soil provides good drainage, which is important for cotton crops because excess moisture can lead to diseases such as root rot and fungal infections. 

Explanation:

Fine clayey soils have a higher water-holding capacity than other soil types, which helps retain moisture and provides a consistent water supply to the wheat plants. Clayey soils are rich in nutrients such as potassium and magnesium, which are essential for the growth and development of wheat plants.

Explanation:

Soils can be classified into three main categories: Sandy, Clayey, and Loamy. Sandy soil has a high proportion of sand particles, with very little silt or clay. Clay soil has a high proportion of clay particles, with very little sand or silt. This soil type is heavy and poorly drained but has high fertility and water-holding capacity. Loamy soil has a balanced mixture of sand, silt, and clay particles, with a high percentage of organic matter.

Explanation:

Soil moisture refers to the amount of water held in the soil and is an important factor in plant growth and ecosystem function. Soil moisture is the water in the pore spaces between soil particles and is essential for the uptake of water and nutrients by plant roots.

Explanation:

Parent Material, climate, organisms, time, and human activities are the factors that make the soil dependent. These factors interact with each other to influence the properties and characteristics of the soil. Understanding the nature of the soil is important for managing soil fertility, conservation, and sustainable agriculture practices.

Explanation:

Silt is a type of soil particle intermediate in size between sand and clay. Silt particles are often found in deposits left by rivers and streams and are present in many soils. Silt particles are typically smooth and round and are often carried along by water currents. Because of their small size and smooth shape, silt particles can easily be transported by wind and water, making them important agents of erosion and sedimentation.

Explanation:

The process of soil formation begins with the weathering of rock and mineral material in the parent material. As weathering proceeds, the parent material breaks into smaller particles, accumulating organic matter and forming distinct soil horizons or layers. Living organisms such as plants, animals, and microorganisms play an important role in soil formation. Climate and topography also influence soil formation by affecting the rate of weathering and erosion, the amount of rainfall, and the temperature and moisture levels in the soil. 

Explanation:

On a hot summer day, the air near the ground is heated by the warm soil, causing it to expand and become less dense. This creates a layer of air with a lower density than the air above it, which causes light waves to bend as they pass through this layer.

Explanation:

Clayey soil has a good water-holding capacity, which is important for rice cultivation as it requires a lot of water for its growth. Clayey soil also has a good nutrient-holding capacity and provides adequate support for the rice plant. It also helps to prevent soil erosion, a major issue in rice cultivation.

Explanation:

Weathering is the natural process by which rocks and minerals are broken down into smaller pieces through the action of physical, chemical, or biological agents. It is an important part of the rock cycle, which describes the continuous transformation of rocks and minerals over time.

Explanation:

Sandy soil retains the least amount of water, while clayey soil retains the most. This is because sandy soil has large pore spaces between its particles, which allows water to drain quickly through the soil. In contrast, clayey soil has small pore spaces between its particles, creating a high surface area and a strong attraction to water molecules, allowing it to hold onto water for longer periods. 

Explanation:

Soil is a complex mixture of mineral particles, organic matter, water, air, and living organisms that provide the physical, chemical, and biological support necessary for plant growth. The mineral particles in the soil provide a stable structure for plant roots to anchor themselves, while the organic matter provides essential nutrients and helps to retain water. 

Explanation:

Clayey soil has a high water-holding capacity and can retain moisture for long periods. This property is particularly useful in areas with limited rainfall or where irrigation is not readily available. Clayey soil is rich in nutrients, including potassium, calcium, and magnesium. This makes it ideal for growing crops that require these nutrients, such as vegetables, fruits, and grains.

Explanation:

The amount of rainfall and temperature can influence the rate of weathering, erosion, and organic matter decomposition, which affects the soil structure. The slope and aspect of the land can impact the amount of water and nutrients available to the soil, as well as the degree of erosion and weathering.

Explanation:

Living organisms in the topsoil play important roles in soil fertility and plant growth. They include bacteria, fungi, earthworms, insects, and other micro and macro-organisms. These organisms break down organic matter, making nutrients available for plant growth, and create soil structure and porosity, allowing air and water to penetrate the soil. This also allows roots to grow and access nutrients and water.

Explanation:

The living organisms in topsoil help to maintain soil structure and prevent soil erosion. Earthworms' burrowing and tunneling activities, for example, help create channels in the soil that allow water to penetrate the soil and roots to grow. Overall, topsoil is a vital component of healthy soil and supports the diverse community of living organisms essential for soil fertility and plant growth.

Explanation:

Polythene bags and plastics are non-biodegradable and can persist in the environment for hundreds of years. They often end up in landfills or the natural environment, where they can cause litter and pollution. Polythene bags and plastics can be mistaken for food by wildlife and can cause harm to them if ingested. Animals can also become entangled in plastic bags, which can cause injury or death.

Explanation:

Horizons are layers of soil that are differentiated based on their physical, chemical, and biological properties. Soil horizons are formed by the natural processes of soil development, which include weathering, erosion, organic matter accumulation, and other soil-forming processes.

Explanation:

The best topsoil for growing plants is loam. Loamy soil is a mixture of sand, clay, and another type of soil particle known as silt. The loamy soil also has humus in it. It has a good water-holding capacity for the growth of plants.

Explanation:

Clayey soil has a high water-holding capacity due to its small pore spaces, which can hold water tightly. This means that clayey soil can retain moisture for longer periods, which can benefit plant growth in areas with limited rainfall. Because of its small pore spaces, clayey soil has poor drainage. This can lead to waterlogging and harm plant growth if not managed properly.

Explanation:

It is the foundation for all life on Earth. Soil is a complex mixture of organic and inorganic materials that support plant growth, sustain animal life, and provide food for humans. Soil is essential for growing crops, which provide food for humans and animals. The nutrients in the soil are absorbed by the plants and used for growth, and the organic matter in the soil helps maintain soil fertility.

Explanation:

Sandy soil has excellent drainage, meaning water moves through it quickly. This can be both a benefit and a disadvantage, as it can lead to drought stress for plants if the soil is not rinsed properly. Sandy soil is not very fertile, as the large sand particles do not hold onto nutrients very well.