The correct option is Over-irrigation.
Explanation
Land degradation refers to the decline in the productive capacity of land due to various natural and human-induced factors. In India, the primary causes of degradation vary significantly across different geographical regions based on dominant economic activities and land-use patterns.
Analysis of Causes by Region
- Over-irrigation (Correct): In the states of Punjab, Haryana, and Western Uttar Pradesh, the primary cause of land degradation is over-irrigation. Intensive agriculture in these regions has led to waterlogging, which increases the salinity and alkalinity of the soil, thereby reducing its fertility.
- Overgrazing: This is the main cause of land degradation in states such as Gujarat, Rajasthan, Madhya Pradesh, and Maharashtra, where pastoral activities are prominent.
- Mining and Quarrying: These activities are the major drivers of land degradation in mineral-rich states like Jharkhand, Chhattisgarh, Madhya Pradesh, and Odisha. Mining sites leave deep scars and traces of overburdening on the land.
- Deforestation: While deforestation is a widespread issue, it is specifically cited as a major cause in states like Odisha, Jharkhand, and the Himalayan region, rather than the intensive agricultural plains of the northwest.
Key Takeaway
Over-irrigation is the specific anthropogenic cause of land degradation in the Green Revolution belts of Northwest India, leading to soil salinity and waterlogging.