Consider the following statements with reference to alluvial soils in ...
Statement 1: Khadar and Bhangar soils contain kankars.
Khadar and Bhangar are two types of alluvial soils found in India. Khadar soils are younger and more fertile, while Bhangar soils are older and less fertile. Both types of soils are formed by the deposition of silt and clay carried by rivers. However, kankars are not typically found in these soils. Kankar is a type of calcareous concretion that is formed by the deposition of calcium carbonate in the soil. It is commonly found in arid and semi-arid regions but not in alluvial soils. Therefore, statement 1 is incorrect.
Statement 2: Alluvial soils are rich in phosphorus but poor in potash.
Alluvial soils are formed by the deposition of sediments carried by rivers. These sediments are rich in minerals and nutrients, making alluvial soils highly fertile. However, the nutrient composition of alluvial soils can vary depending on the parent rock material and the depositional processes. Generally, alluvial soils are rich in both phosphorus and potash. Phosphorus is essential for plant growth as it plays a key role in energy transfer and cell division. Potash, which refers to potassium compounds, is also important for plant growth as it regulates water uptake, enzyme activation, and overall plant health. Therefore, statement 2 is incorrect.
Statement 3: The alluvial soils are predominantly sandy in nature.
Alluvial soils are formed by the deposition of sediments carried by rivers. These sediments include various particle sizes such as sand, silt, and clay. The composition of alluvial soils can vary depending on the source of the sediments and the depositional processes. While alluvial soils may contain sandy particles, they are not predominantly sandy in nature. Alluvial soils can have varying proportions of sand, silt, and clay, resulting in different soil textures. The presence of different particle sizes contributes to the fertility and water-holding capacity of alluvial soils. Therefore, statement 3 is incorrect.
In conclusion, statements 1, 2, and 3 are all incorrect. Alluvial soils in India do not typically contain kankars, are rich in both phosphorus and potash, and have varying proportions of sand, silt, and clay.
Consider the following statements with reference to alluvial soils in ...
- The alluvial soils vary in nature from sandy loam to clay. They are generally rich in potash but poor in phosphorous. Hence statements 2 and 3 are not correct.
- In the Upper and Middle Ganga plain, two different types of alluvial soils have developed, viz. Khadar and Bhangar.
- Khadar is the new alluvium and is deposited by floods annually, which enriches the soil by depositing fine silts. Bhangar represents a system of older alluvium, deposited away from the flood plains.
- Both the Khadar and Bhangar soils contain calcareous concretions (Kankars). These soils are more loamy and clayey in the lower and middle Ganga plain and the Brahmaputra valley. Hence statement 1 is correct.
- The sand content decreases from the west to the east.
- Alluvial soils are not very deep in nature. Black soils are very deep in nature.
- The particles that make up soil are categorized into three groups by size – sand, silt, and clay. Sand particles are the largest and clay particles the smallest. Most soils are a combination of the three. The relative percentages of sand, silt, and clay are what give soil its texture. A clay loam texture soil, for example, has nearly equal parts of sand, slit, and clay. This textural separates result from the weathering process.
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