Confronting the challenges of salinity intrusion on agriculture in South Asia

Salinity intrusion—accelerating due to sea level rise and coastal erosion—is leading to contamination of surface water and groundwater reserves, wetlands loss, and various public health risks. It makes the livelihoods of many people dependent on fisheries and agriculture increasingly uncertain.

It will take a multi-sectoral approach to adapt to the challenges of salinity intrusion. The costs of response measures could be immense. Effective adaptation requires a strategic investment plan that identifies priority areas of intervention to allocate limited financial resources.

The densely populated coastal regions of Bangladesh and India are especially at risk. This is why IFPRI, in collaboration with the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) and the Borlaug Institute for South Asia (BISA), organized a one-day stakeholder meeting on climate change induced salinity intrusion in coastal Bangladesh and India in Dec. 2018.

The meeting focused on three main issues:

• The impact of salinity intrusion on livelihoods, crop production, and other agricultural systems, aquatic ecosystems, and infrastructure.
• Various adaptation methods and techniques currently adopted by different stakeholders and the scope for further upscaling.
• The best practices across regions, including the constraints and opportunities for knowledge transfer across the international border with similar agro-climatic conditions.

A.K. Singh, Deputy Director General of the Indian Council of Agricultural Research (ICAR), emphasized the need to develop a coordinated strategy for the future as the area under salinity increases due to climate change.

Wais Kabir, Executive Director of Krishi Gobeshona Foundation, noted that the seasonal nature of salinity in coastal Bangladesh already requires adjusting cropping patterns accordingly.

Information and communications technology-based tools are crucial to disseminate timely and accurate information to cultivators to facilitate decision making, said Sheetal Sharma of the International Rice Research Institute (IRRI). These tools can be used to broadcast customized advisories with respect to nutrient requirement, fertilizer use, stress forecasting, etc.

The meeting generated suggestions for future research and policy recommendations, the adoption of a multi-sectoral approach to minimize the risks posed by salinity intrusion. These include:

• The three main categories of adaptation measures—technological solutions, management practices, and institutional capacity—provide a workable starting point towards building long-term strategies related to climate change induced salinity intrusion.
• There is a need to develop multi-stress tolerant cultivars, in addition to the existing salt-tolerant varieties, to foster resilience to address increasing climate-driven weather uncertainties.
• Varietal development should go hand-in-hand with salinity mapping of coastal areas for promoting soil health. Knowing the concentration and nature of salinity can help in assessing the location-specific needs of cultivars.
• The success of climate-smart agriculture (CSA) depends on the availability and management of fresh water in coastal areas. An integrated water resource management approach must be adopted to reduce the stress on available resources and prevent contamination.
• Improved Doruvu technology—which skims fresh water floating on saline groundwater—has proven to be an efficient method in coastal Andhra Pradesh, India. The limitations of Doruvu technology, especially in sandy regions, must be further studied if it is to be upscaled.
• Sluice gates contain salinity, but their operation also creates conflicts due to the clashing interests of rice farming and shrimp farming. Community management of sluice gates in a mutually beneficial manner is vital to adapt to salinity intrusion. Many polder regions in Bangladesh are using this opportunity to more efficiently manage water flows.
• Farmers’ organizations should be formed based on catchment area and hydrological limit of sluice gates rather than the administrative limits, as is done currently in most areas.
• Eco-technological concepts such as Tidal River Management (TRM) can be explored for areas where natural flows are suitable.
• Any new intervention for farmers in coastal regions must be studied from the cost-benefit perspective from upstream to downstream for a comprehensive risk assessment. Similarly, projects should incorporate strengthening of grassroots-level institutions and gender equity to ensure the sustainability of new interventions.
• Agricultural labor shortages are one of the major problems in salinity affected areas. This is due to migration and the overlap of public programs with the cropping season. Although Bangladesh achieved substantial growth in mechanization to replace animal labor, more emphasis must be placed on human labor substitute mechanization for crop cultivation.
• There is a need for immediate, coordinated, and a recursively dynamic approach towards policymaking in coastal Bangladesh and India to safeguard the livelihoods of millions of people living in these regions.

The challenge posed by salinity intrusion can be seen as an opportunity to sustainably enhance agricultural and aquacultural productivity—and the incomes of people living in these regions. IFPRI will continue its collaboration with CCAFS in the second phase of the project to evaluate alternative policies and institutions and develop investment plans to adapt to climate change. Among the aims are developing investment prioritization models and future climate action plans to tackle the adverse effects of salinity intrusion.

Read more: Climate change induced salinity intrusion and its implications for agriculture

Himanshu Pathak is an IFPRI Research Analyst; Barun Deb Pal is an IFPRI Project Manager; P.K. Joshi is IFPRI’s South Asia Director. They are based in IFPRI's South Asia Office in New Delhi. This post first appeared on the CCAFS blog.