Which isohyet separates major Rice and Wheat producing areas in India?

Question

Accepted Answer

The 100 cm isohyet (Option 3) is considered the approximate dividing line between the major rice and wheat producing areas in India.

*   **Why Option 3 (100 cm) is correct:** Rice, being a water-intensive crop, thrives in regions with high rainfall. Areas receiving more than 100 cm of rainfall annually are generally suitable for rice cultivation. Conversely, wheat requires less water and is typically grown in regions with lower rainfall. The 100 cm isohyet roughly marks the transition zone where rainfall is sufficient for rice cultivation to be dominant, while areas to the west and northwest, receiving less than 100 cm, are more suited for wheat production. This is a generalization, and other factors like soil type and irrigation also play a role, but the 100 cm isohyet serves as a useful indicator.

*   **Why Option 1 (75 cm) is incorrect:** While some wheat cultivation occurs in areas receiving around 75 cm of rainfall, this amount is generally insufficient for widespread rice cultivation. Therefore, it doesn't effectively separate the major rice and wheat producing zones.

*   **Why Option 2 (50 cm) is incorrect:** 50 cm of rainfall is significantly low for rice cultivation. Areas receiving this little rainfall are primarily arid or semi-arid and are not suitable for major rice production. Wheat can be grown in these areas with irrigation, but 50 cm isohyet does not represent the boundary between major rice and wheat areas.

*   **Why Option 4 (125 cm) is incorrect:** While areas receiving 125 cm or more of rainfall are excellent for rice cultivation, this isohyet doesn't represent the *separation* between major rice and wheat areas. Areas receiving this much rainfall are almost exclusively rice-growing regions, and the transition to wheat-dominant areas occurs at a lower rainfall threshold.