The Sundarbans, one of the world’s largest mangrove ecosystems spanning coastal eastern India and western Bangladesh, is also among the most climate-vulnerable regions in South Asia. Island and coastal communities face repeated cyclones, tidal flooding and saline water intrusion. Agriculture is increasingly threatened, as saline water damages fields and destroys traditional seed systems. The rabi (dry-winter) season is particularly challenging. Paddy fields often remain fallow due to limited crop options under increased soil salinity, limited fresh water for irrigation and high labour costs in the context of male labour migration.
Potato zero-tillage with rice straw mulching (PZTM) is emerging as a promising climate-resilient solution in this context. Building on earlier research by ICAR-Central for Soil Salinity Research Institute (CSSRI) in 2015, International Potato Center in collaboration with ICAR-CSSRI and Nature Environment and Wildlife Society (NEWS) have been conducting participatory research for development on this technology in Sundarbans, West Bengal India. This blog shares insights from our experience engaging with over 1,400 farmers in last three years.
What is PZTM and Why Does it Matter in a Salinity context?
PZTM is a conservation agricultural practice where potatoes are planted directly into rice fields without ploughing the soil. Rice straw is used as mulch to conserve moisture, suppress weeds, and reduce soil temperature fluctuations. The system minimizes soil disturbance, reduces irrigation requirements, and lowers labour demand compared to conventional potato cultivation by manual labour. Since the tubers are grown inside rice straw instead of soil, it remains clean, increasing shelf-life. The technology is particularly beneficial in the regions with high soil- and water-salinity, such as the Sundarbans, where fresh water is limited and the soil is too wet to plough.
Reaching Hundreds of Farmers Across the Sundarbans
Over the last three years, we have introduced PZTM in North and South 24 Parganas districts, West Bengal, India including remote islands in the Sundarbans. In the 2025-26 crop season, a total of 52.5 metric tons of potato seed were distributed by road and boat to 1,476 farmers (35% women-managed plots), contributing to greening 35 hectares of land, many of which would otherwise have been left fallow. Among them, 127 plots (68% women-managed plots) implemented organic PZTM with the focus on the quality and sustainability of potato production. Although there are various technological challenges to be addressed, feedback from farmers is positive, especially from women farmers.
Why does PZTM Work for Women?
Women in the Sundarbans are already deeply engaged in protecting mangroves, nurturing livestock, maintaining local seeds and responding to climate risks. They often explain to us how storms, tidal surges, and saline flooding regularly damage agricultural land. Yet, their roles in agriculture are considered secondary to men who are major decision makers and managers of rice production.
However, PZTM enables women to manage production with a sense of ownership and control. In some cases, women perform all activities independently or collectively through women’s groups. There are two major reasons for that. First, although men consider paddy fields as their own productive assets, they leave paddy fields unused during the dry season, as there is little value in the land when soil salinity increases. Women are therefore free to use fallow land, creating opportunities to access land and cultivate potatoes. Furthermore, zero tillage does not require land preparation, which is considered a man’s domain. Harvesting is also easy since potatoes appear lying on the ground after removing rice straw.
“Now, we recognize ourselves as farmers,” said Ms. Annapurna Parya from the Sagar Island explaining how the project transformed women’s roles in her community.
She explained that before participating in PZTM, many women, including herself, did not consider themselves farmers. Women were viewed mainly as helpers to their husbands. Training provided to women enabled them to independently manage production activities from planting to harvesting and selling. This experience significantly strengthened their confidence and recognition as farmers. She also reflected on the broader climate context. While island communities possess rich traditional agricultural knowledge, adapting to climate change requires new technologies and approaches. She expressed pride in the fact that women are leading this transition.
She also described how PZTM changed the landscape itself. Traditionally, the village appears brown and dry during the rabi season. But with widespread PZTM adoption, the fields remained green throughout the winter months. For many residents, this was the first time they had seen such greenery during the dry season, creating optimism and interest among neighbouring farmers who now plan to follow their lead in the coming year.
Ms. Manasi Mandal from Hingalganj, located along the Bangladesh border, emphasized that PZTM is particularly suitable for areas facing freshwater shortages during the rabi season. She provided us feedback through her first experience of PZTM with advice such as the need for advance preparation for inputs such as organic manure and requirement for earlier-maturing potato varieties adapted to local conditions in crop rotation with long-duration rice varieties. Insights provided by women farmers enable researchers to improve technologies to respond to local needs.
Building Seed Security and Linking to Markets
One of the major challenges in the Sundarbans is the long distance from seed-producing areas in India. It is costly for smallholder farmers to purchase quality seed every year, while net-house seed production requires a long-term investment. To address this challenge in the short term, NEWS supported the preservation of subsequent-generation seed for the next planting season by storing them in cold storage. In this cropping season, 199 farmers collectively stored their seed (19 tons) at a cooperative cold storage facility in North 24 Parganas. Establishing community-led sustainable seed systems remains an important agenda for scaling PZTM in the Sundarbans.
In addition, facilitating market opportunities is particularly important in the remote islands, where limited transportation and high costs isolate island communities from markets. Some potatoes have been sold directly to local retail outlets without going through middlemen, and around 480 kg have already been sold within 1.5 months of harvesting. Another two tons of potatoes were purchased from farmers and stored in a cold storage for retail sales later when market prices increase. The farmers benefited from better selling prices, as they received ₹1–2/kg more than prevailing local market prices.
A Pathway Toward Climate Resilience
This project demonstrates that vulnerable communities are not passive victims. By providing enabling environment for women, the communities are creating new opportunities for sustainable livelihoods in the rabi season. In the Sundarbans, PZTM has contributed to greater confidence among women farmers, leading to greener winter landscapes and enhanced food security.
Like other conservation agriculture technologies, PZTM is not a perfect solution to climate change. Based on continuous feedback from participating farmers, the interdisciplinary team at International Potato Center and its partners has been addressing key adoption constraints such as developing partially and fully mechanized PZTM methods, rodent management strategies, localized protocols for organic PZTM, and context-specific variations of PZTM building on farmer practices. As climate pressures intensify, scaling locally adapted PZTM could play a critical role in supporting resilient agriculture across fragile coastal ecosystems in South Asia.
Written by Nozomi Kawarazuka, Dhiman Burman, Goutam Mukherjee, Tashi Dorjee Lama, Uttam Kumar Mandal, Saikat Manna.
Acknowledgement: The project was funded by Ministry of Foreign Affairs and Trade of New Zealand, CGIAR Initiative on Asian Mega Deltas (2022-24) and CGIAR Science Program on Scaling for Impact AoW2 (2025) and implemented in collaboration with IRRI, ICAR-CSSRI and NEWS.