The correct option is (a).
Explanation
Terrace farming is an agricultural technique primarily utilized in hilly and mountainous regions. It involves cutting steps or "terraces" into steep slopes to create flat areas of land suitable for crop cultivation. This method is crucial for managing water resources and preventing soil degradation in areas with significant gradients.
Statement-wise Analysis:
- Statement 1 is Correct: Terrace farming is practiced on steep slopes. The terraces are constructed to create flat surfaces on the hillside. This design allows water to stand on the field rather than flowing away immediately, which is essential for the cultivation of water-intensive crops such as paddy. It effectively conserves water by reducing the speed of surface runoff.
- Statement 2 is Incorrect: Terraces are not built on flat plains. They are specifically carved out of slopes to create flat land where none existed naturally. In flat plains, the natural topography already supports agriculture without the need for terracing.
- Statement 3 is Incorrect: The slope is not increased; rather, the steepness is removed or broken down into flat steps. The objective is to ensure that water does not run off rapidly. Rapid runoff leads to soil erosion and water loss. By flattening the slope, the velocity of water flow is checked, allowing for infiltration and preventing the washing away of topsoil.
Key Takeaway:
Terrace farming converts steep slopes into flat steps to check surface runoff and prevent soil erosion, thereby retaining soil moisture and fertility for agriculture in mountainous regions.