The soil conservation method in which fields are ploughed and cultivated parallel to the natural contours of a hill slope so that ridges act as barriers that slow down the flow of water is known as which of the following?

Introduction / Context:
Soil conservation techniques are important in geography and environmental science. Hilly areas are especially vulnerable to soil erosion because rainwater can flow rapidly down slopes, washing away topsoil. Different methods, such as contour ploughing, terrace farming and mulching, are used to reduce this erosion. This question focuses on identifying the specific method where ploughing is done parallel to the contour lines of the hill slope.

Given Data / Assumptions:

• The method described involves ploughing parallel to the contours of a hill slope.
• The purpose is to form a natural barrier that slows water flow and reduces erosion.
• Options include mulching, contour barriers, contour ploughing, terrace farming and strip cropping.

Concept / Approach:
A contour is a line on a map or a field that connects points of equal elevation. When ploughing is done along these lines instead of straight up and down the slope, small ridges and furrows are formed that hold water and reduce its speed. This is called contour ploughing. It is different from terrace farming, which creates flat step like fields, and from contour barriers, which focus on physical barriers such as stone or grass strips rather than the direction of ploughing itself.

Step-by-Step Solution:
Step 1: Identify the key phrase in the question: ploughing done parallel to hill slope contours.Step 2: Recall that contour ploughing specifically refers to cultivation along contour lines.Step 3: Understand that this technique reduces the speed of runoff water and increases water infiltration into the soil.Step 4: Compare with terrace farming, which involves cutting the slope into step like flat terraces, not just directing ploughing along contours.Step 5: Choose contour ploughing as the method that best matches the description given.

Verification / Alternative check:
You can verify by remembering typical textbook diagrams: contour ploughing shows curved plough lines that follow the shape of the slope, whereas terrace farming shows horizontal steps. Mulching, strip cropping and contour barriers may accompany contour ploughing but are different methods described separately in geography notes.

Why Other Options Are Wrong:
Mulching: This involves covering the soil surface with straw, leaves or plastic to reduce evaporation and erosion, not ploughing along contours.
Contour barriers using stone or grass strips: These are physical embankments placed along contour lines, but the question specifically mentions ploughing, which is a different technique.
Terrace farming with step like fields: Terrace farming reshapes the land into wide steps, not simply ploughing parallel to natural contours.
Strip cropping in alternate rows: This method grows crops in alternating strips to reduce erosion but does not specifically require ploughing parallel to contour lines.

Common Pitfalls:
Students often confuse contour ploughing with terrace farming because both are used on slopes. The key distinction is that terrace farming changes the land profile into steps, while contour ploughing keeps the slope but changes the direction of ploughing and cropping. Paying attention to the exact wording of the question will help avoid such confusion in exams.

Final Answer:
The described soil conservation method is called contour ploughing along the slope contours.