The correct answer is: All of the above.
Irrigation is important for agriculture in Manipur, especially in the Imphal Valley, Hilly regions, and River valleys.
The Imphal Valley is a fertile plain that is home to most of Manipur’s population. The valley is well-suited for agriculture, but it receives less than 1000 mm of rainfall per year. This means that irrigation is essential for growing crops.
The Hilly regions of Manipur are covered in forests and mountains. The climate in the hills is cooler and wetter than in the valley. However, the soil in the hills is not as fertile as the soil in the valley. This means that irrigation is also essential for growing crops in the hills.
The River valleys of Manipur are located in the north and south of the state. The rivers in these valleys provide water for irrigation. The river valleys are also home to some of Manipur’s most important agricultural areas.
In conclusion, irrigation is important for agriculture in Manipur, especially in the Imphal Valley, Hilly regions, and River valleys.