Examkin

Soru

Zorluk: OrtaSoils, Natural Vegetation, and Agriculture in India

Consider the following statements regarding Black Soil (Regur Soil) in India:

1. It is rich in soil nutrients such as calcium carbonate, magnesium, potash, and lime, but generally poor in nitrogen and phosphorus contents.
2. Due to its high clay content, it develops deep cracks during dry summers, which aids in soil aeration through a process often called 'self-ploughing'.
3. It is predominantly formed by the alluvial deposition of the Ganga and Brahmaputra river systems in northern India.

Which of the statements given above is/are correct?

  1. 1 and 2 onlyCevap
  2. B
    1 and 3 only
  3. C
    2 and 3 only
  4. D
    1, 2 and 3

Cevap

Statements 1 and 2 are correct. Black soil is rich in calcium carbonate, magnesium, potash, and lime, but deficient in nitrogen, phosphorus, and organic matter. High clay content causes it to swell when wet and shrink when dry, forming deep cracks that facilitate self-ploughing. However, it is formed by weathering of Deccan basaltic lava, not alluvial river deposits.
The combination indicating 1 and 2 only is correct because Black Soil contains calcium carbonate, potash, lime, and magnesium, and its clayey nature creates deep cracks upon drying ('self-ploughing'). Statement 3 is false because Black Soil originates from lava rocks of the Deccan Plateau, whereas northern plains consist of alluvial soil.

Adım Adım Çözüm

1
Evaluate Statement 1 regarding chemical composition of Black Soil.
Statement 1 is correct. Black soil (Regur) contains high amounts of lime, iron, magnesium, alumina, and potash, but lacks nitrogen, phosphorus, and humus.
Pedological studies of Deccan trap soils confirm this mineral signature.
2
Evaluate Statement 2 regarding physical characteristics and moisture retention.
Statement 2 is correct. High clay content gives black soil high moisture retention; drying causes reticulate cracking that aerates lower soil horizons ('self-ploughing').
Shrink-swell behavior of montmorillonite clay minerals causes this structural phenomenon.
3
Evaluate Statement 3 regarding geographic origin and distribution.
Statement 3 is incorrect. Black soils are residual soils derived from Deccan trap basalt rocks found across Maharashtra, Madhya Pradesh, Gujarat, and northern Karnataka, whereas alluvial soils dominate northern river plains.
Geological origin of regur soil is parent basaltic rock weathering, not river sediment deposition.

Anahtar Kavram

Black Soil (Regur) Physical Properties, Chemical Profile, and Geographical Distribution in India
Bu soruyu puanla

Konular

Soils, Natural Vegetation, and Agriculture in India

Bu konudan daha fazla soru