Thanjavur, Tamil Nadu: Dinesh Pandidurai and other farmers like him in Ozhugaserry, in the Anakarai panchayat of Tamil Nadu’s Thanjavur district, have decided to forego work for Samba, the summer paddy crop.

Prolonged and increased heat and the failure of monsoons have dried the groundwater in the region, even in fields that are just 100 metres from the Kollidam river. To make matters worse, increased salinity has made the groundwater unfit for use.

The two issues are connected by the process of reverse osmosis: As heat and lack of rain forces the water table down, sea water ingresses into the space and pollutes the groundwater. The salt rises to the topsoil and covers the crops in a thin white film.

Most of the farmers installed submersible bore wells to access fresh water deep down and carried on cultivation for a year, only to find that the young saplings acquired moss formation and died. "Saline groundwater is affecting the soil and roots too," Pandidurai explains. "It is preventing the roots from getting sunlight and nutrients. So, the crops get burned."

The usual crop cycle in the region comprises Samba, which is a 145-day cycle that begins around August; Kuruvai, a 120-day cycle that ends in June-July; and Thaladi, a 135-day cycle that is sown in September-October. Farmers here say they have cut it down to just two crops a year and, in some rain-fed regions, to just one crop annually.

“Global warming, an expression of climate change, may result in 1 to 1.5 degree Celsius temperature increase in another 15-20 years,” explains G.A. Dheebakaran, associate professor of agronomy at the Agro-Climate Research Centre in Tamil Nadu Agricultural University (TNAU), Coimbatore. “Agricultural crop production is highly sensitive to increasing temperature. Scientists have proved through different crop simulation models that temperature increase is more detrimental than any other weather parameters, and even one degree increase in temperature may result in 10-25% yield reduction."

He pointed out that as minimum temperatures are increasing at a higher rate than maximum temperatures, it reduces the diurnal variation in temperature between day and night. "This causes high respiration loss, and that is another reason for yield reduction," Dheebakaran said. Rising temperature is leaving less time for the crops’ vegetating phase when photosynthesis takes place. In the case of paddy, this phase has been reduced by at least 10 days from the original 60 days, he explained, leading to lean or ill-filled grain.

Ground salinity and pests

Rising temperatures present multiple roadblocks to cultivation in the Cauvery delta region, especially in the Thanjavur-Tiruvarur belt, approximately 325 km south-west of the Tamil Nadu capital, Chennai. “Both excess rains and severe drought have affected cultivation,” says M. Jaishankar, Farm Team, Swami Dayananda Educational Farms in Manjakudi village of Tiruvarur district. "Temperatures have risen up to 49 degree Celsius during May-June this year. As a consequence, the salinity level in the ground has been increasing up to 8.9 pH value so far.”

In order to adapt to the change, farmers started to follow a different cropping pattern. Now, Samba cultivation starts only in September and ends in February. This has a knock-on effect: Traditionally, cultivation of pulses in fallow land after the rice harvest begins around January 14 and ends in April. This helps to fix nitrogen in root nodules, and this will be passed on to the paddy crop after the pulse harvest. But this year, even this pattern was upset due to rains received during mid-January. So farmers have stopped cultivating pulses, and shifted to cotton cultivation from February to August.

This shift in crop patterns has been neither beneficial nor cost-effective. Priyanka Navneet, Spirit of the Earth, an experience centre and retail store that promotes cultivation and conservation of folk rice varieties, Chennai tells us how: “Though salinity in groundwater supports cotton cultivation, it needs extensive pest management. 99% of the farmers growing existing varieties such as GMO-BT use banned pesticides, fertilisers and weedicides in the cotton field to boost production. This kills the soil's natural fertility and eventually leads to less productivity.”

Also, cotton needs at least six sessions of irrigation. Since groundwater sources have either dried up or sunk deep, most farmers use submersible borewells that go up to 200 feet underground to irrigate the cotton fields, and small-time cultivators rent the borewells. This further depletes groundwater and drives the water table deeper--and even after all this, last year the harvest fetched them Rs 55,000-56,000 per quintal. The prices kept fluctuating between Rs 45-58 per kg, but expenses shot up to Rs 60,000 per acre.

The cost versus reward calculus

“I use an oil engine pump set for irrigation," Azhaghar said. "One litre of diesel runs for 45 minutes; I need 10 litres of diesel to irrigate one acre. At that rate, we spend Rs 1,000 or thereabouts per acre on fuel alone.

"Cotton needs irrigation once every fifteen days. I spent Rs 5,000 per acre for water. Additionally, I rented the tubes, at the rate of Rs 100 for every 100 feet. Labourers have to be paid, at Rs 400 per person for every 30 kg of harvest. Add transportation expenses, loader charges and vehicle rent, and at the end we earn around Rs 1,000 from 30 kg of cotton.”

Azhagar cultivated three acres in 2021 when the price was Rs 110 per kg, and he made a substantial profit. Excited, he cultivated five acres in 2022, but the prices fell, and he is now back to cultivating three acres this year. To fix price inconsistency and to provide a strong livelihood opportunity, says Azhagar, “price determination is the only way forward. Given the expenses, Rs 100 per kg will work out well for farmers.”

Then there is paddy, for which the cost of cultivation is around Rs 40,000 per acre. At best, the yield is about 1,800 to 2,000 kg. The produce is sold either in 60-kg bags, for Rs 1,200 per bag, or in the direct purchase centre-regulated 40-kg bags, which are sold at Rs 800 per bag.

If the field is irrigated with river water, then they do not incur expenses on water. In its absence, Azhagar says, they use diesel pumps to flood the fields. “Paddy needs to be irrigated at least 10 times per crop season of cultivation. If a motor pump for irrigation is rented, the rent amount ranges from Rs 4,500-Rs 6,000 per acre. If they own a pump, diesel costs come up to Rs 400 per acre.“

Thus, neither the cost of cultivation can be contained nor profits are substantial. This presents a major hindrance to paddy cultivation.

Same is the case for cotton, says Azhagar. “Since it’s a six-month cycle and the irrigation sessions are more, the rent charges for water are at Rs 9,000 per acre. Adding all these up, the cost of cultivation goes up from Rs 3,600 to Rs 4,000 per acre.”

In addition, climate change-specific pest attacks such as rice stem borer, which attacks paddy crops in the Samba and Kuruvai season, the brown plant hopper that attacks high-yielding paddy varieties, and wild boar attacks observed in paddy fields in the Tiruvarur district adds to the farmers' plight.

“The Cauvery delta is the 'Rice Bowl' of Tamil Nadu," the scientist from TNAU says. "Either reducing the area under rice cultivation, or the promotion of crop diversification during the main season under normal release of Cauvery water and during normal monsoon, will impact the yield of rice.

"In order to counteract this, TNAU, through its advisory wing advises farmers to go for less water-intensive crops such as maize, cotton, pulses and sesamum, if drought or low water release is forecast in this region. This alternate wet and dry method of irrigation will also reduce the methane contribution from wet land agriculture.”

The government pitches in to provide guidance and help. Subsidies are available for seeds and other inputs, rent of tractors for ploughing, levelling and harvesting operations, and procurement through Direct Purchase Centres (DPC).

Through regional radio stations, the Rice Research Institute, Aduthurai, and through agri news channels, farmers receive weather forecasts and related information on a daily basis. TNAU provides district-level seasonal rainfall forecasts for both the south-west and north-east monsoons with 60% accuracy.

TNAU also provides village-level medium range weather forecast (rainfall, temperature, relative humidity and windspeed) for the next six days with an over 70%. The University is also promoting weather-based response farming, that is, farming based on the information from technocrats, which involves weather forecast, pest attacks. This information is passed on to the farmers through field visits that TNAU advisory wing does along with corresponding adaptations to be done in the fields.

The road ahead

This year, severe drought from August to the first week of October has stopped the farmers from raising nursery for the Samba season 2023. According to the rainfall registry at the Agriculture office at Kudavasal, the monthly average rainfall is 153 mm. The yearly average is around 1,710 mm. But the total rainfall between August and October 2023 was 174.3 mm. Farmers have also been advised against using their own seeds obtained from a hybrid crop, since this could give low yield in the next generation.

Generally, farmers prefer medium duration varieties for the Samba season (135 days crop). But due to climate change, farmers are keen to cultivate short duration varieties which can be sown after October 15 and harvested during January, which is approximately 78-80 days per cycle.

"Varieties like IR 20, ADT 42, ADT 43 with duration around 120 days and average yield per acre between 2,000-2,500 kg are specific varieties that have been moderately successful in Tiruvarur district," says Priyanka Navneet of Spirit of the Earth.

But Jayapal Kaliyaperumal, a farmer from Adthamangalam in Sirkazhi, in Tiruvarur district, claims that even traditional varieties like ADT-38 and ADT-46 are not as productive as they are touted to be. “Last year I cultivated Kichili Samba; back then, rainwater was helpful. This year I have gone for Thooyamalli and Seeraga Samba varieties. The yield is progressively less. With very less rain this time, direct sowing is also not taking off," he told IndiaSpend.

Same is the case with the rain-resilient varieties. Pandidurai tells us that the resilience threshold is broken. "CR-1009-Savitri-Sub 1, a long-term paddy crop variety, falls down in the rain, and too much sunlight turns it into hay."

With no return on investment except for large-scale farmers, already farmers are giving up and moving to other occupations. Farming is no longer the preferred or sustainable choice anymore. "In my grandfather’s days, in the 1950s, the profit from one bag of paddy was enough to buy one sovereign (8 gm) of gold (about Rs 56,000 today)--now, we don't earn anywhere close to that," says Dinesh. "With Samba, Kuruvai and now Thaladi cultivations at risk, the price of rice could shoot up in January.”

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