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A mysterious decline in his harvests leaves a farmer searching for a solution » Yale Climate Connections

Whenever people notice the stunted sugar cane plants on Babar Kamble’s farm in India’s Maharashtra state, he tells them: “My farm is dying a slow death.”

It started in 2014 when production on Kamble’s farm slid five metric tons lower than the 80 metric tons he normally harvested from his one-acre field. He shrugged off that year’s decline, chalking it up to bad weather, but the following year he was alarmed when he lost 10 more metric tons.

“I thought increasing the use of chemical fertilizers would help boost the production,” he recalled. It did help — for two years. He kept boosting chemical fertilizer use until he was using over 1,000 kilograms for an acre, more than triple the 300 kilograms he used in 2000, his first year of fertilizer use. But the effect was the opposite of what he expected. Harvests resumed their steady decline until Kamble’s farm managed just 35 metric tons in 2023, a 56% fall from 2013.

“I’ve been farming since childhood but never reported such a major decline,” said Kamble, 54, whose farm is in Maharashtra’s Shirdhon village.

The problem was salt

Some fertilizers contain high levels of salts such as potassium chloride or ammonium sulfate. Spreading large quantities of such fertilizers increases soil salinity, harming crops.

In India, soil has already been getting saltier in an era of rising sea levels and heavy floods followed by periods of less rain to flush the salt from the soil. And in the face of increasingly bad weather, farmers’ consumption of chemical fertilizers has increased by a staggering 95% between 2000 and 2021, reaching an all-time high of 32.5 million metric, according to the Fertilizer Association of India.

With crop yields falling despite greater irrigation and heavier fertilizer use, farmers are earning less income to pay back their mounting debts. The problems look insurmountable, but some farmers see promise in sustainable farming methods, innovative but expensive underground pipe systems, or switching to crops that require less water to thrive.

7 million hectares salinized

“When I used to help my father during childhood, I only used organic fertilizers like animal manure, compost, and leftover crops,” Kamble said. But now, “If I don’t use chemical fertilizers, my crops won’t grow. As I keep adding more fertilizer, my soil gets even more saline. I am caught in this vicious cycle.”

Kamble said he fears that “my field will be reduced to a barren wasteland within a few years.”

Other Indian farmers are caught in a similar conundrum. Soil on 147 million hectares of land has been degraded in India, roughly 1,875 times the size of New York. Of this, soil salinity has degraded roughly 7 million hectares, and 10% of the additional area is getting salinized every year. At this pace, experts estimate that by 2050, half the arable land will be salinized.

Climate change is one culprit. In a warming world, melting glaciers are boosting sea levels, which is also boosting soil salinity as saltwater seeps into coastal lands. The global average sea level already has risen by eight to nine inches since 1880.

“Because of climate change, in some regions, the winter monsoon is becoming drier,” which means that rainfall, already scant during this period, is diminishing further,” explained Fabien Durand, senior scientist at the Institute of Research for Development, Laboratory of Studies in Space Geophysics and Oceanography, France. “Usually, this rainfall helps flush out the saline water.” Less rain means “there’s nothing to oppose the entry of saline waters from the ocean.”

Increased flooding has exacerbated the problem of rising sea levels and increasing use of chemical fertilizers. A 2019 study found that after a short-term floodwater event, elevated salt levels were seen in the soil’s topmost layer, though it washed off eventually with heavy rainfall.

Floods in India destroyed crops on 34.8 million hectares of farmland between 2015 and 2020, affecting over 218 million people. Prolonged droughts followed by intense floods that release and redistribute salts from geological substrates have put more areas in India at risk of soil salinization.

Kamble and other farmers witnessed extended periods of dry days after the floods that drowned their fields for around a month in 2019 and 2021.

During the 2021 floods, Kamble’s wife Sarita recalled, “The water was at least 22 feet in our field, and we couldn’t enter the farm for a month.”

About 11 kilometers from Kamble’s field is farmer Rajendrakumar Chougule’s farm in Maharashtra’s Akiwat village, known for its black alluvial soil with good organic content. Farming experts were puzzled when the 10-month-old sugar cane spread across three acres in his field grew only a foot in 10 months.

“Ideally, it should have been at least five-seven feet tall by now,” said Chougule, 61.

To speed up growth, “I used a lot of chemical fertilizers, even sprayed chemical pesticides, removed the weeds on time, but nothing worked.” He blamed soil salinity, which started degrading the fields in his village a decade back and has affected over 200 farmers there.

Depleting groundwater and mounting debt

Even with intermittent floods, Chougule says, drought has depleted groundwater tables, forcing him to dig a borewell.

“Almost every farmer here has a borewell at least 400 feet deep,” he says.

Increasingly extreme heat waves have been drying up water sources, forcing farmers to pump out more groundwater. As the water table depletes, saline water from the rising sea levels leaches into the once-fresh groundwater and contaminates it.

As water beneath the crops recedes, plants pull water from deeper soil layers, and the dissolved salts in the groundwater move closer to the surface. As temperatures rise, more water evaporates from the soil surface, leaving behind salts in the upper layer.

Fertilizers and chemical pesticides also flow into rivers or leach into the soil, reaching groundwater that is in turn fed to crops, further increasing soil salinity.

A 2023 study found that a 1°C increase in the mean temperature was associated with a reduction in groundwater gain during the monsoon and an increase in groundwater withdrawal during winter, despite the positive effects of rainfall that recharged the water table.

If the trend continues, a 1°C warming in monsoon and winter could lead to a staggering annual groundwater depletion of eight to 36 centimeters across India. Between 2041 and 2080, India is projected to lose groundwater at a rate more than three times higher than the current depletion rate, with climate change expanding the range of groundwater depletion.

With losses mounting, farmers increasingly rely on loans, which are hard to pay off as crop yields decline. Kamble took a loan of 127,000 Indian rupees ($1,525). The government recovers the loan from the sugar cane that farmers send to the factory.

“Even after selling all my sugar cane, I still owe the bank Rs 79,000 ($947),” he said.

In India, soil salinity and sodicity — a specific type of soil salinity problem — lead to a loss of 16.8 million metric tons of crops every year, causing a loss of 276 million USD. As soil salinity increased, so did Kamble’s debt, taking a toll on his mental, physical, and financial health. He had to find another way to earn money and took a job as a security guard in an industry 27 kilometers away.

Sustainable farming solutions

a man smiles at the camera, holding tall plants in his armsa man smiles at the camera, holding tall plants in his arms
Farmer Narayan Gaikwad has grown pearl millet for over six decades. Because pearl millet remains one of his favorite millets, he often hugs it, expressing gratitude to his ancestors who preserved the crop. (Photo credit: Sanket Jain)

Some think solving this crisis depends on a deep rethinking of farming practices and even the choice of crops. Roughly 10 kilometers away from Kamble’s field lies the three-acre farm of Narayan Gaikwad, who is renowned for practicing sustainable farming.

Gaikwad, 77, has been farming for over six decades and uses organic fertilizers.

“While this does lead to lesser production, it has kept my soil healthy,” he noted. He and his wife, Kusum, 66, also grow different types of indigenous millet varieties like finger and pearl millets. Crops like sugar cane and rice guzzle water and are sensitive to saline soils.

It takes about 250 metric tons of water to produce a ton of sugar cane, whereas millets need as little as 20 cm of rainfall and can even grow in saline soils. And they need no chemical fertilizers or pesticides, preventing the leaching of salts.

Still, most farmers in India prefer to grow sugar cane because it has a guaranteed procurement system, ensuring farmers earn something. But continuing to do so will require them to solve the problem of waterlogged soils and poor drainage, which adds to salinity. Some are turning to subsurface drainage systems using underground pipes to help remove excess salts in the root zone of plants. Farmers in Akiwat and several other villages of Western Maharashtra have found this method helpful, but Chougule, who has not installed it yet, noted that few farmers can afford it.

In Vietnam’s Mekong Delta, farmers have adopted rice-prawn rotational farming as another innovative approach. They cultivate rice during the rainy season when fresh water is available and shift to prawn farming in the dry season. Prawns boost nutrients in the soil, helping to decrease the use of chemical fertilizers for cultivating rice. Also, Fabien Durand suggests, “In coastal areas, farmers can adopt salt-tolerant rice varieties, but its seeds are expensive.”

Every day, Kamble and Chougule think about what they can do to save the soil.

“My father always told me that soil is your wealth,” Kamble said. “I never took it seriously, but today, when I see soil salinization around me, I understand what he meant by that.”

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