Changes in rice cultivation can curtail climate change

New Delhi : At a time when climate change is set to impact rice production in Asia, simple water management by farmers as an adaptation strategy will minimise the damage. "Climate change will impact rice production in large parts of Asia, including India. Water management will be a key feature of decisions aimed at adapting to the impacts of climate change," Dennis Wichelns, Senior Research Fellow of Thailand-based Stockholm Environment Institute (SEI), said during the Knowledge Forum on Climate Resilient Development in Himalayan and Downstream Regions held in New Delhi recently.

The event was organised jointly by the Ministry of Agriculture and Farmers Welfare, Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD) and Delhi-based IEG. According to Wichelns, improvement in water management will help in areas where higher temperatures are likely and where shift in rainfall pattern is expected. In certain areas, crop yields will increase in some seasons, perhaps in response to higher rainfall during the production cycle or with a reduction in summer days in the northern regions. In other areas, yields might be reduced due to higher night temperatures, untimely drought conditions, or submergence caused by massive natural events.

According to Wichelns, improvement in water management will also help in reducing methane emissions and arsenic uptake in the rice fields. "Methane is a potent greenhouse gas. It is estimated that up to 20 per cent of the anthropogenic releases of methane to the atmosphere are generated in agriculture, largely by livestock and in rice production," he said. "The anaerobic conditions in which paddy rice is produced is largely responsible for the methane generation and release. Methanogenic organisms, which thrive in anaerobic conditions, break down carbonaceous materials and form methane," he added.

Switching from flooded paddy production to aerobic rice production or to alternative crops that are produced in aerobic conditions can substantially reduce regional methane emissions. Arsenic accumulation in rice grain declines sharply when farmers switch from anaerobic to aerobic production methods. Millions of residents of South and Southeast Asia already are exposed to harmful concentrations of arsenic in drinking water. "If farmers remove the water for seven to 10 days mid-season, they can substantially reduce methane generation and release. The paddies are re-watered after the de-watering, but the methanogenic organisms will have been greatly reduced during those seven to 10 days," Wichelns stressed.

By Imran Khan