Transitioning to Low-Carbon, Resilient Rice Production in Pakistan

The rice cultivation area in Pakistan has expanded by 29% in the last 10 years, contributing significantly to farmers’ livelihoods, food security, and national economy. Rice exports surged by 95% over the last decade, making it the country’s second largest export, contributing $3.7 billion to the national foreign exchange reserves. The province of Punjab accounts for 69% of total rice production.

Environmental impacts

Despite these gains, expanding rice production comes with sustainability challenges due to its high environmental impact, particularly in terms of carbon emissions and water usage. The traditional practice of continuously flooding rice paddies creates low-oxygen environment in soil, leading to substantial methane emissions—a potent GHG that accelerates climate change. This irrigation method also results in high evaporative water losses, making rice cultivation the largest consumer of freshwater in Pakistan.

Rice is the largest consumer of irrigation water used in the country, while contributing only 1% to its GDP. Although recent reforms in Punjab shifted water pricing mechanisms to crop-specific rates from a flat rate per acre to promote crop diversification, the changes were ineffective. Low water prices failed to incentivize the adoption of water-saving technologies. Small landholdings without on-farm water storage systems further undermine efforts to improve water use efficiency, as farmers cannot store excess water for future use.

In Punjab, the leading rice growing province, more than 50% of irrigation water is sourced from groundwater, threatening a decline in groundwater levels in areas served by several canals. In addition, the government’s subsidies for solar-powered tube wells in Punjab—introduced without sufficient consideration of groundwater sustainability, could exacerbate the problem because the high price of electricity and fuel incentivizes judicious use of groundwater.

Meanwhile, Sindh—the second largest rice-producing province—faces a different challenge. While groundwater in most of Sindh is not suitable for irrigation, competition for water among various sectors has led to a continuous reduction in water availability for rice farming.

Environmental credentials

With increasing focus on sustainability, agricultural industries are expected to demonstrate their environmental credentials, particularly in markets such as Europe that import rice from Pakistan. The prospect of future carbon tax implications further incentivizes the production of low-carbon rice.

However, the lack of actual quantification and national capability in quantifying GHG emissions from rice fields mean that claims about the carbon footprint of rice and its mitigation potential are anecdotal, with limited credibility and authentication.

Additionally, the large variability across country’s rice ecosystems results to significant uncertainties in estimating emissions from rice production using the current standards of the national GHG inventory.

To track the country’s progress and ensure transparency, it is crucial to establish a scientific national GHG inventory. This would enable Pakistan to meet its national targets while providing a transparent framework for the agricultural sector and other industries.

ADB is supporting Pakistan’s adoption of alternate wetting and drying–a transformative approach to promote sustainable rice practices. Unlike the current practice of continuous flooding, alternate wetting and drying is a water management method that involves periodically drying rice fields for a few days between periods of flooding. This process has been proven to reduce water use in intensive rice systems by 30% and GHG emissions from 30% and 70%. But the potential of alternate wetting and drying to save water and reduce GHG emissions has not been investigated in Pakistan.

Data from the first year of the pilot study—investigating the benefits of alternate wetting and drying in reducing GHG emissions and improving water productivity—collected from Punjab’s Sheikhupura and Okara districts are currently being analyzed to show the initial effects of this method on Pakistan’s rice production. This collaborative study also involves international stakeholders, such as the International Rice Research Institute (Philippines), the University of Philippines, and Karlsruhe Institute of Technology (Germany).

The alternate wetting and drying pilot in Punjab consists of two trials:

• A scientific study measuring GHG (methane and nitrous oxide) emissions from alternate wetting and drying and farmer practice treatments at the Rice Research Institute (Sheikhupura) and at On Farm Water Management Research Farm (Okara).
• Farmers trial in Sheikhupura and Okara districts to investigate the water productivity and alternate wetting and drying adoption barriers and opportunities.

The study is the first of its kind in Pakistan to estimate GHG emissions from rice systems, aiming to develop country-specific (Tier 2) emission factors for rice cultivation using the Intergovernmental Panel on Climate Change-recognized scientific methods. This will enhance the accuracy of the country’s GHG inventory and provide essential data for carbon market initiatives.

The study will also identify and address barriers preventing rice growers from adopting alternate wetting and drying and propose effective strategies to encourage its widespread adoption in Punjab's rice cultivation. The trials will generate relevant data to establish robust evidence on the benefits of alternate wetting and drying to increase water productivity and profitability of rice production under Pakistan’s specific environment.

In addition, the trials will serve as a platform for building the capacity of researchers and agricultural agencies, equipping them with the knowledge and skills to implement, monitor, and report on alternate wetting and drying practices and GHG emissions at the national level.

In the absence of an effective water pricing mechanism, farmers need incentives to be encouraged to adopt alternate wetting and drying. Carbon markets presents one such opportunity as alternate wetting and drying is an accepted technology in these markets.

However, the financial viability of a carbon market project would depend on alternate wetting and drying’s potential to reduce GHG emissions compared to the baseline emissions from the traditional continuous flooding method. The study will generate crucial GHG data that will help assess the potential of alternate wetting and drying in developing viable carbon market projects in Pakistan.

Implementing a carbon market project using alternate wetting and drying for rice system would also require a transparent system for monitoring, reporting, and verification. This includes enabling technologies, such as water level remote sensing, which would allow for regular monitoring and simplify reporting and documentation for accurate verification. These sensors would address the constraints of tedious water level monitoring, making it easier for farmers to adopt alternate wetting and drying practices. The project will also evaluate on-farm automated water level monitoring systems, which would alert farmers when to irrigate and how to do so efficiently—reducing the frequency of irrigation and overuse of groundwater.

Takashi Yamano, Rubenito Lampayan, M. Radanielson, Thi Bach Thuong Vo, and Babur Wasim contributed to this article.

Food and Agriculture Organization of the United Nations. 2013. Rice Farming: Saving Water Through Alternate Wetting Drying (AWD) Method, Indonesia.

Rice Knowledge Bank. Saving Water with Alternate Wetting Drying (AWD). International Rice Research Institute.

GHG Mitigation in Rice. Alternate Wetting and Drying.