Groundwater depletion and winter cropping intensity

Context:

Study of India’s main irrigation types on winter cropped areas finds that that 13% of the villages in which farmers plant a winter crop are located in critically water-depleted regions.

Relevance:

GS-III: Agriculture (Agricultural Resources, Issues related to agriculture and food security)

Dimensions of the Article:

1. The current scenario on Winter Cropped Areas and Irrigation types
2. Reasons for Depletion of Groundwater
3. Alternative sources
4. Unsuited soils and poor infrastructure

The current scenario on Winter Cropped Areas and Irrigation types

• India is the second-largest producer of wheat in the world, with over 30 million hectares in the country dedicated to producing this crop.
• But with severe groundwater depletion, the cropping intensity or the amount of land planted in the winter season may decrease by up to 20% by 2025.
• Some of the important winter crops are wheat, barley, mustard and peas.
• The international team studied India’s three main irrigation types on winter cropped areas: dug wells, tube wells, canals, and also analysed the groundwater data from the Central Ground Water Board.
• They found that 13% of the villages in which farmers plant a winter crop are located in critically water-depleted regions.
• The team writes that these villages may lose 68% of their cropped area in future if access to all groundwater irrigation is lost. The results suggest that these losses will largely occur in northwest and central India.

Reasons for Depletion of Groundwater

• Increased demand for water for domestic, industrial and agricultural needs and limited surface water resources lead to the over-exploitation of groundwater resources.
• There are limited storage facilities owing to the hard rock terrain, along with the added disadvantage of lack of rainfall, especially in central Indian states.
• Green Revolution enabled water intensive crops to be grown in drought prone/ water deficit regions, leading to over extraction of groundwater.
• Frequent pumping of water from the ground without waiting for its replenishment leads to quick depletion.
• Subsidies on electricity and high MSP for water intensive crops is also leading reasons for depletion.
• Water contamination as in the case of pollution by landfills, septic tanks, leaky underground gas tanks, and from overuse of fertilizers and pesticides lead to damage and depletion of groundwater resources.
• Inadequate regulation of groundwater laws encourages the exhaustion of groundwater resources without any penalty.
• Deforestation, unscientific methods of agriculture, chemical effluents from industries, lack of sanitation also lead to pollution of groundwater, making it unusable.

Alternative sources

• The team then looked at canals to understand if they can be promoted as an alternative irrigation source and as an adaptation strategy to falling groundwater tables. But the results showed that “switching to canal irrigation has limited adaptation potential at the national scale. We find that even if all regions that are currently using depleted groundwater for irrigation will switch to using canal irrigation, cropping intensity may decline by 7% nationally”.
• We can conjecture based on other literature and say that adoption of water-saving technologies like a sprinkler, drip irrigation and maybe switching to less water-intensive crops may help use the limited groundwater resources more effectively.

Unsuited soils and poor infrastructure

• There are several first-generation (productivity) and second-generation (sustainability) problems. In the green revolution era, policy-supported environment led to a large increase in rice cultivation in northwestern India mainly in Punjab and Haryana which are ecologically less suitable for rice cultivation due to predominantly light soils.
• This policy-supported intensive agriculture led to unsustainable groundwater use for irrigation and in turn groundwater scarcity.
• There was also post-harvest residue burning to make way for the timely sowing of wheat.
• There are enough groundwater resources supported with higher monsoon rainfall in eastern Indian states like Bihar. But due to lack of enough irrigation infrastructure, farmers are not able to make use of natural resources there.
• So, we need better policies in eastern India to expand the irrigation and thus increase agriculture productivity. This will also release some pressure from northwestern Indian states.

-Source: The Hindu