In a recent study, it was discovered that severe groundwater depletion in India could lead to a significant reduction of winter cropped acreage in the future. The research studied the effects India’s three primary irrigation types—dug wells, tube wells and canals—have on winter cropped areas. Notably, winter crops mainly consist of wheat, barley, peas, gram and mustard. The researchers also utilized groundwater data provided by the Central Ground Water Board.
Understanding the Current Situation
Since the 1960s, India has made commendable strides in food production, primarily due to an increased reliance on irrigation wells. This has enabled Indian farmers to extend their production window into the mostly dry winter and summer seasons. Presently, India stands as the world’s second-largest producer of wheat and rice, with over 600 million farmers in the country. It accounts for 10% of the world’s crops. However, India is now the world’s largest consumer of groundwater, leading to rapidly depleting aquifers across most of the country.
During the green revolution era, policy-supported farming environments facilitated a massive increase in rice cultivation in northwestern India, particularly in Punjab and Haryana. These regions are ecologically less suitable for rice cultivation because of predominantly light soils. This intensive agriculture strategy, supported by policies, led to harmful groundwater usage for irrigation and resulted in groundwater scarcity.
The Study’s Findings: Groundwater Depletion
Groundwater is crucial for food security, contributing to 60% of irrigation supplies in India. However, excessive consumption of groundwater for irrigation and domestic use is causing its depletion. It is projected that groundwater depletion in India could reduce food crop output by up to 20% nationally and around 68% in regions projected to register low future groundwater availability by 2025. Statistics illustrate that 13% of villages where farmers plant a winter crop are in critically water-depleted regions. The losses are expected to mostly occur in northwest and central India.
The Potential of Canal Irrigation
The Indian government has proposed a switch from groundwater-depleting wells to irrigation canals as one way to overcome projected shortfalls. Irrigation canals divert surface water from lakes and rivers. The study, however, suggests that canal irrigation has limited adaptation potential at the national scale, and that switching to canal irrigation might not fully compensate for the expected loss of groundwater in Indian agriculture. Furthermore, compared to tube well irrigation, canal irrigation was associated with less winter cropped area, rendering it more sensitive to rainfall variability.
Groundwater Depletion’s Impact on Crop Production
The depletion of groundwater may lead to a reduction in cropping intensity, which means fewer crops will be grown from the same field in a year. Even if all regions currently using depleted groundwater switch to canal irrigation, cropping intensity could still decline by 7% nationally and 24% in the most severely affected locations. The irrigation canals would favour farms close to them, leading to unequal access.
A decrease in crop area will mainly impact states that grow wheat, potentially leading to significant reductions in future wheat production. Given that India is the second-largest producer of wheat globally, which provides around 20% of household calories in India, a lower wheat output could threaten food security.
The Concept of Cropping Intensity
Cropping intensity refers to the number of crops raised from the same field during one agricultural year. It is calculated using the formula: Cropping Intensity = Gross Cropped Area/Net Sown Area x 100.
Currently, about 51% of India’s geographical area is under cultivation, compared to the world average of 11%. Since independence, the country’s cropping intensity of 136% has only increased by 25%. Rainfed drylands make up 65% of the total net sown area.
Central Ground Water Board’s Role
The Central Ground Water Board is a subordinate office of the Ministry of Jal Shakti. It is the national apex agency responsible for providing scientific input for the management, exploration, monitoring, assessment, augmentation and regulation of groundwater resources in India. The board was established in 1970 by renaming the Exploratory Tubewells Organization under the Ministry of Agriculture. It was later merged with the Groundwater Wing of the Geological Survey of India in 1972.
The Way Forward:
To address these issues, better policies are needed in eastern India to expand irrigation and increase agricultural productivity. This could relieve some pressure from northwest Indian states. States like Bihar, for example, have substantial groundwater resources and higher monsoon rainfall but lack sufficient irrigation infrastructure, causing farmers to underutilize natural resources.
Adoption of water-saving technologies like sprinklers or drip irrigation and switching to less water-intensive crops in certain areas may also be crucial in using limited groundwater resources more effectively.