Joshua Mendoza

Published: April 11, 2024

SCIENCE CITY OF MUÑOZ, Philippines — Farmers in Nueva Ecija, the Philippines’ rice granary, and some parts of Central Luzon can expect extra income through a cash incentive for adopting a water-saving technology called alternate wetting and drying (AWD).

This initiative not only benefits farmers financially but also combats climate change. By practicing AWD, farmers reduce methane emissions from rice production and earn carbon credits. 

Engineer Evangeline Sibayan of carbon management solutions provider Ostrom Climate Solutions Inc. said farmers practicing AWD will receive around $30 to $35 per hectare each year, with the potential for an increase if the voluntary market carbon price rises.

Sibayan added the AWD technology can reduce methane emissions from rice cultivation by up to an average of 50% carbon dioxide equivalent (CO2e) annually.

Paddy rice cultivation accounts for 8% of human-caused methane emissions, according to the United Nations Environment Programme. Methane is 80 times more potent at warming the planet than carbon dioxide over a 20-year period. 

The project, a partnership between Ostrom Climate Solutions Inc. and National Irrigation Administration-Upper Pampanga River Integrated Irrigation Systems (NIA-UPRIIS), aligns with Article 6.4 of the Paris Agreement, which established an international carbon crediting mechanism in the voluntary market. 

“This carbon credit is called internationally transferrable mitigation outcomes (ITMOs) which can be traded internationally… In our project, the mitigation activity is the adoption of AWD,” Sibayan said. 

After three cropping seasons, the project has trained around 7,000 rice farmers from Irrigators Association (IAs) in Guimba and Science City of Muñoz in Nueva Ecija.

The initiative is targeted to be rolled out in the entire service area of Upper Pampanga River Integrated Irrigation Systems, which also includes some parts of Tarlac, Bulacan, and Pampanga.  

Alternate wetting and drying technology

A farmer participates during a training on Alternate Wetting and Drying technology. (Ostrom Climate Solutions Inc.)

Introduced by the International Rice Research Institute (IRRI) and Philippine Rice Research Institute (PhilRice), AWD involves intermittent irrigation of rice fields. This allows the soil to dry out, monitored through an observation well using a perforated PVC pipe inserted 15 centimeters into the ground. 

When the pipe is empty, irrigation is applied, and the cycle is repeated. To ensure no yield reduction, ponded water of not more than 5 cm is maintained during fertilizer application and flowering and grain filling.

Under the traditional continuous flooding method, farmers need around 2,500 to 4,000 liters of water to produce 1 kilogram of unhulled rice. 

Meanwhile, AWD has been reported to reduce water consumption by 25%, and in some cases, even up to 30%. It is expected that rice farmers at the tail-end of the irrigation system can still be reached.

“As an example, If there are 1,000 hectares that adopted AWD, there will still be 250 hectares more that can benefit from the water saved by the former,” Engr. Sibayan said.

The Department of Agriculture is ramping up the implementation of AWD to help Filipino farmers weather the impacts of El Niño.

Sibayan also cited studies showing this technology can increase yield by 5%.

However, a major challenge in adopting AWD is older farmers’ reluctance to try new practices. Despite this, Sibayan is hopeful the ongoing annual incentives will motivate them to embrace AWD technology.