Reducing greenhouse emissions in Agriculture
Almost half the workforce in Bangladesh is engaged in agriculture, mostly focusing on rice production as it is our staple food (Pearson, Millar, Norton, & Price, 2018). Rice production is therefore essential for both our economic wellbeing and food security. However, Bangladesh faces multiple challenges in rice production, especially dependence on groundwater for irrigation in context to climate change (Islam & Nursey‐Bray 2017) which has resulted in aquifer depletion and increase in salinity.
About 62 percent of farmers use only groundwater while 11.3 percent use surface water for irrigation; the rest do not depend on irrigation but rely on rainwater (Ahmed et al., 2013). Dependence on irrigation pump surges during the dry season which stresses the national grid and increases dependence on diesel-powered pumps (Ahmed et al., 2013).
Arsenic is another problem associated with rice production. Due to the presence of Arsenic in groundwater, the use of groundwater in irrigation results in Arsenic exposure on consumption. According to 2007 Intergovernmental Panel on Climate Change (IPCC) report globally, 13.5 percent of anthropogenic Green House Gas (GHG) emission comes from Agriculture, of which rice cultivation results in significant GHG emission, especially methane. It has been estimated that flooded rice systems (comprised of irrigated, rainfed and deep-water rice) accounts for 11 percent for all the anthropogenic greenhouse gases (Smith, 2012).
The technique of Alternate Wetting and Drying (AWD) can significantly decrease the stressors as mentioned above of rice cultivation, especially the dependence on irrigation and arsenic contamination to the existing farming practices in Bangladesh.
AWD is a management practice used to irrigate lowland rice; this is a practice of periodic drying and re-flooding of the rice field. Some of the benefits of AWD have been identified to reduce water use by 30 percent and GHG emissions by 50 percent while maintaining rice yields.
The use of AWD technique first began in China and India in the 1980s and 1990s respectively (Mushtaq, Dawe, Lin, & Moya, 2006), but it was in 2002 when the Philippines first evaluated it as a water‐saving practice. Bangladesh Rice Research Institute (BRRI) had its first trial of AWD in Bangladesh in 2005 (Lampayan, Rejesus, et al., 2015). Even though evidence from AWD trials and demonstrations in Bangladesh has shown significant benefits for the farmers, but unlike farmers in China and the Philippines, Farmers in Bangladesh have been least interested in adopting this technology.
However recently under the project, Mitigation Options to Reduce Methane Emissions in Paddy Rice International Rice Research Institute IRRI and its implementing partners BRRI and Rangpur Dinajpur Rural Service (RDRS) has made some significant changes in reintroducing AWD in Northwest Bangladesh. A recent workshop titled, “Large Scale Implementation of Alternate Wetting and Drying (AWD) Technology in Bangladesh” held on 4th May 2019, highlighted how AWD is being promoted in Rangpur and Dinajpur through the Focal Area Network (FAN).
FAN is a rice-based multi-sectored network in Northwest Bangladesh, and this network comprises of farmers, organizations, academia, NGO’s and government agencies. Due to multi-stakeholder collaboration, out-scaling the AWD to thousands of farmers has been made possible this time around. Moreover, this project focuses on the collaboration of farmers and pump owners where both parties work together to map out irrigation strategies.
The impact study presented at the workshop highlighted that when combined with climate-smart agriculture options, namely nutrient management, sustainable residue management, benefits from the AWD technique can be maximized. A majority of the farmers under the project had experienced an increase in the yield.
Farmers also claimed that their urea use had decreased by 25 percent. Apart from water saving from AWD technology, arsenic uptake by rice plants are also decreased by reducing the length of time the rice is growing anaerobically, and this may lower arsenic contamination in rice.
Article 8 of the revised Bangladesh National Agriculture Policy states the importance to promote AWD technology in agriculture, Bangladesh being a Signatory of Paris Climate Agreement, is committed to curbing its GHG emissions. As rice production is a significant contributor to Bangladesh's carbon emissions, AWD presents an opportunity to help address our emission targets.
Moreover, this is not only a climate-smart but also a water-smart technology, with more benefits than losses, and tried method of multi-stakeholder collaboration learned from the IRRI project AWD seems like a win/win situation for us.
Rukhsar Sultana is an Intern at ICCCAD and has an MA in Environmental Studies with a background on wastewater management and plastic pollution.