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प्रश्न
What is the soil profile? Explain the characters of different soil horizons.
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उत्तर
| Horizon | Description |
| O-Horizon (Organic horizon) Humus SamacheerKalvi.Guru | It consists of fresh or partially decomposed organic matter. 01 - Freshly fallen leaves, twigs, flowers, and fruits. O2 - Dead plants, animals, and their excreta decomposed by micro-organisms. Usually absent in agricultural and deserts. |
| A-Horizon (Leached horizon) Topsoil - Often rich in humus and minerals. | It consists of topsoil with humus, living creatures, and in-organic minerals. A1 - Dark and rich in organic matter because of the mixture of organic and mineral matters. A2 - Light-colored layer with large-sized mineral particles. |
| B-Horizon (Accumulation horizon) (Subsoil - Poor in humus, rich in minerals) | It consists of iron, aluminum, and silica-rich clay organic compounds. |
| C - Horizon (Partially weathered horizon) Weathered rock Fragments - Little or no plant or animal life. | It consists of parent materials of soil, composed of a little amount of organic matter without life forms. |
| R Horizon (Parent material) Bedrock | It is a parent bedrock upon which underground water is found. |
संबंधित प्रश्न
Read the given statements and select the correct option.
- Hydrophytes possess aerenchyma to support themselves in water.
- Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
- Hygroscopic water is the only soil water available to roots of plants growing in soil as it is present inside the micropores.
- High temperature reduces use of water and solute absorption by roots.
Read the given statements and select the correct option.
Statement A: Cattle do not graze on weeds of Calotropis.
Statement B: Calotropis have thorns and spines, as a defense against herbivores.
In soil water available for plants is
The plant of this group are adapted to live partly in water and partly above substratum and free from water
Ophrys an orchid resembling the female of an insect so as to able to get pollinated is due to phenomenon of
In a fresh water environment like pond, rooted autotrophs are
Strong, sharp spines that get attached to animal’s feet are found in the fruits of
Sticky glands of Boerhaavia and Cleome support
The organic horizon is generally absent from agricultural soils because tilling, e.g., plowing, buries organic matter. Why is an organic horizon generally absent in desert soils?
Soil formation can be initiated by biological organisms. Explain how?
Sandy soil is not suitable for cultivation. Explain why?
Describe the mutual relationship between the fig and wasp and comment on the phenomenon that operates in this relationship.
What is thermal stratification? Mention their types.
What is co-evolution?
Read the following statements and fill up the blanks with the correct option.
- Total soil water content in soil is called ______
- Soil water not available to plants is called ______
- Soil water available to plants is called ______
Column I represent the size of the soil particles and Column II represents the type of soil components. Which of the following is the correct match for the Column I and Column IL
| Column - I | Column - II | ||
| I) | 0.2 to 2.00 mm | i) | Slit soil |
| II) | Less than 0.002 mm | ii) | Clayey soil |
| III) | 0.002 to 0.02 mm | iii) | Sandy soil |
| IV) | 0.002 to 0.2 mm | iv) | Loamy soil |
