It is hailed as India's granary, but the northwestern state of Punjab faces a drastic decline in agricultural output unless it halts the rapid depletion of its groundwater, experts warn.

Groundwater irrigates almost three-quarters of Punjab's agricultural land, but groundwater levels are dropping by 40 to 50 cm (16 to 20 inches) a year, according to Rajan Aggarwal, head of the soil and water engineering department at Punjab Agricultural University (PAU).

That has left farmers like Ajmir Singh struggling as their irrigation wells dry up. "We are not able to find water even if we go down to 200 feet (61 m) or more at some places," said Singh, who has farmed for 35 years in Jalandhar, 150km (95 miles) north of Chandigarh, the state capital.

His neighbour, Pawanjeet Singh, said lack of irrigation water has forced him to sell part of the land that has been in his family for generations to a large-scale farmer who has the resources to drill for water at much deeper levels.

"I took this decision with a heavy heart after I realised that drawing water for all my land is beyond my means," Singh said.

According to Aggarwal, groundwater has been overexploited in 110 of the state's 138 administrative blocks.

"This is alarming given that more than 73% of irrigation is taken care of by groundwater," he said.

Experts say dealing with the problem, in the region that led India's Green Revolution in the 1970s, will require a rapid shift away from crops that require large amounts of water, such as rice and wheat, to less-thirsty pulses, maize, vegetables and sugarcane to safeguard the state's agricultural economy.

Rice and wheat make up 81 % of Punjab's irrigated crops, according to a report by PAU. Although the state accounts for only 1.5 % of India's geographical area, over the past two decades it has contributed 35 % of the nation's rice production and 60 cent of its wheat.

LOW RAINFALL

According to Sunil Jain, regional director of the Central Ground Water Board for northwest India, groundwater started dropping in 1985 in Punjab, and has sunk to alarming levels in recent years.

Thirty years ago farmers in most parts of the state could draw water at a depth of 10 metres (32 ft), but by 2015 this was 20 metres, while farmers in some central parts of the state are unable to find water even at 30 metres or deeper, he said.

"There has been a substantial rise in groundwater utilisation, which has mainly happened because of the fact that Punjab gets less rainfall. Since paddy (rice) requires a lot of water, the farmers resort to heavy usage of groundwater for irrigating the paddy fields," he said.

Jain added that Punjab gets less than 700mm of rainfall annually. This compares to a national average of 1,083mm, according to the World Bank.

Amit Kar, an economist at the Indian Council of Agricultural Research, attributed the groundwater shortage to government policies such as free electricity for irrigation, credit facilities and subsidies for digging wells and buying pumping equipment, as well as heavily subsidised diesel fuel for pumps.

The PAU report said annual demand for irrigation in Punjab is 4.76 million hectare metres (mhm) against a total annual supply of 3.48 mhm from canal and groundwater resources.

The deficit is met by overexploitation of deeper groundwater by farmers using nearly 1.4 million tube wells, which exacerbates the loss of more accessible groundwater. According to the PAU report, 3.5 million of Punjab's 9.1 million workers make a living from agriculture or associated activities.

Jain said the statistics suggest Punjab's agricultural success may not be sustainable

"Punjab's exports of rice and wheat to other regions literally mean the export of its groundwater to those regions," he said.

Amitabh Kant, chief executive officer of the government's National Institution for Transforming India (NITI Aayog), predicted "the present rate of withdrawal will lead to complete exhaustion of groundwater within a decade" in the region.

Kant said India, already water-stressed, is rapidly moving towards becoming water-scarce.

TIME TO SWITCH?

Switching to new crops is one way to ease the problem in Punjab, said PAU's Aggarwal. Rice requires about four times as much water as maize, pulses or oilseeds, for instance.

Vinod Kumar Singh, a scientist at the Indian Agricultural Research Institute, said Punjab must make the shift at any cost.

"The government has to make some policy decisions like assuring the farmers it will procure their produce other than paddy (rice) and wheat. Only then will they be convinced to switch over to these crops," he said.

Under India's state-sponsored Public Distribution System, the national government buys staple foods like rice, wheat and sugar from farmers and sells them to citizens at fair or cheaper prices. Commodities worth $2.25 billion, including rice and wheat, are sold annually to about 160 million families.

Jasbir Singh Bains, Punjab's director of agriculture, said that system makes farmers reluctant to cultivate other crops.

"We have started making efforts to popularise the cultivation of pulses, maize, vegetables and oilseeds," Bains said. "For example, we have appealed to the central government to increase the procurement of pulses and are urging the farmers to grow vegetables, which also have a good market."

Farmers like Shamsher Singh, in Nokdar-Jalandhar, said they would switch to less thirsty crops with government help.

"We are ready for this, but the government should give the guarantee that it will procure our products like it is doing in the case of wheat and rice," he said.