Black soil is ideal for cultivation of cotton as

RRB Staff Nurse Ahmedabad-2015

Non Nursing Subjects

Easy

Appeared in: RRB Staff Nurse Ahmedabad-2015

Explanation

Black soil, also known as Regur soil, has a high water-retaining capacity due to its high clay content (argillaceous nature).
Cotton is a crop that requires consistent and significant moisture for optimal growth, especially during the boll formation stage.
This characteristic of the soil ensures a steady supply of water to the plant's roots over a long period, reducing the impact of short dry spells and the need for frequent irrigation.

Option A: The black color is a physical characteristic resulting from its mineral composition (e.g., titaniferous magnetite). It is not a functional property that aids in crop cultivation.
Option C: This statement describes the origin of black soil (weathering of basaltic lava rocks). While true, the origin itself is not the direct reason for its suitability; the properties that result from this origin (fine clay particles) are what matter.
Option D: This statement describes the geographical distribution of black soil, which is commonly found in plateau regions like the Deccan Plateau. Location is not a property of the soil itself that makes it fertile for cotton.

Visual 1: Map - A map of India highlighting the regions with black soil, primarily concentrating on the Deccan Plateau, to show its geographical distribution.
Visual 2: Diagram - A comparative diagram showing water retention in different soil types (Clay/Black Soil vs. Sandy Soil vs. Loamy Soil), illustrating how clay particles hold more water.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Properties of Black Soil and its suitability for Cotton Cultivation as background academic context rather than a clinical decision trigger.
This topic is part of general knowledge and geography, which is often a component of the preliminary sections in competitive examinations for nursing positions in India.
Understanding the relationship between natural resources (like soil) and economic activities (like agriculture) provides a holistic perspective relevant to community and environmental health.
What if the crop was different? For a crop like millets, which requires less water and well-drained soil, sandy or loamy soils would be more ideal than the heavy, water-retentive black soil.

How to Approach the Question

First, identify the core of the question. It asks for the specific reason ('as') that makes black soil 'ideal' for cotton.
Analyze the options to find a direct cause-and-effect relationship. The question isn't just asking for a true fact about black soil, but the one fact that explains its agricultural benefit for cotton.
Consider the needs of the cotton crop. Cotton requires a lot of water to grow. This is a key piece of information.
Evaluate each option against this requirement. Does the soil's color, origin, or location provide water to the plant?
The only property listed that directly addresses the plant's need for water is the soil's ability to 'retain moisture'. This creates the strongest link and is the most logical answer.

Concept Tested & Keywords

Concept Tested: Properties of Black Soil and its suitability for Cotton Cultivation
Stem keywords: Black soil, cultivation of cotton
Lead-in keywords: ideal for

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