The correct option is Kalibangan.
Explanation
The agricultural economy of the Indus Valley Civilization was supported by advanced techniques, including the use of ploughs. Archaeological evidence from specific sites provides insight into the farming methods and cropping patterns employed during the Early and Mature Harappan phases.
Detailed Analysis:
- Kalibangan: Located in the Hanumangarh district of Rajasthan, this site provides the earliest evidence of a ploughed field. This find is associated with the Early Harappan phase (pre-Harappan levels). The field revealed a grid of furrows, with two sets of furrows crossing each other at right angles. This pattern suggests the practice of mixed cropping, where two different crops (likely mustard and gram) were grown simultaneously on the same field.
- Harappa: While this site contains significant structures like granaries and working platforms for grain processing, no direct evidence of a ploughed field surface has been recovered here.
- Mohenjodaro: Famous for the Great Bath and the Great Granary, this site has not yielded evidence of an intact ploughed field.
- Lothal: Known primarily for its artificial dockyard and evidence of rice cultivation (rice husks), it does not provide evidence of a ploughed field surface.
Key Takeaway: Kalibangan is the specific Harappan site that yields evidence of a ploughed field from the Early Harappan period, characterized by a grid pattern of furrows indicating mixed cropping.