01 October 2019

Simple Method To Grow Climate Friendly Rice

This news is redirected and translated by SCIENCE from Verdens Bedste Nyheder. 
Worldwide, millions of rice farmers halve their emissions of strong greenhouse gasses using low practical methods for watering. The climate potential is huge, Danish expert says.

Rice is one of the most important crops in the word and is the primary source of food for more than half of the world population. However, traditional rice farming emits methane, a greenhouse gas 34 times as powerful as CO2. Experts estimate that rice farming accounts for up to two percent of the world’s emission of greenhouse gasses – almost as much as the global airplane traffic.

Rice has a large need for irrigation and is mostly farmed in flooded fields. Nevertheless, without any oxygen in the soil, microbes within the soil produce methane, which is emitted by the rice plants.

With one simple method, it is possible to halve the emission of methane. Andreas de Neergaard associate dean at University of Copenhagen and PhD in Agroecology, has years of experience with research in climate friendly rice.

”The solution is to oxide the soil. If you drain the fields periodically instead of keeping them flooded, it is possible to reduce the emissions of greenhouse gasses remarkedly,” he says.

Huge climate potential
Together with wheat and corn, rice is one of the largest crops and several hundreds of farmers grow rice.

”Within the farming industry, climate friendly rice farming has a huge potential,” Andreas de Neergaard says.

Norman Uphoff is professor emeritus at Cornell University in New York and he has worked with climate friendly methods for rice farming for a long time. He tells the World Best News that up to 20 million rice farmers worldwide, from Indonesia to Peru, already grow rice with climate friendly watering methods.

Difficult balance
The idea behind climate friendly rice is simple. Soil on drained fields contain oxygen and then methane will not be produced. However, as rice demands a lot of water in order to grow, you cannot just drain the fields as it suits you.

”It is a delicate balance to drain enough water to reduce the emission of methane while avoiding limiting the growth of the rice,” Andreas de Neergaard tells.

Meanwhile, it is a challenge that laughing gas instead of methane is produced after the draining when the soil is half-wet – and laughing gas is a greenhouse gas 300 times more powerful than CO2. Nonetheless, Andreas de Neergaard and his colleagues have proven that by draining the fields once a year, early in the season, it is still possible to reduce the methane without producing laughing gas.

Demands a level of organizing
The biggest hindrance is relatively simple. Many rice fields are connected or terraced, so it is not that simple only to drain one field and then flood it again.

”You have to synchronize the watering system with the rest of the village, so it demands planning in another way than what the farmers are used to in order to control the water,” Andreas de Neergaard explains.

He notices that the challenge therefore has to be solved in a well-organized and political manner e.g. by organizing rice farmers on a village level, establishing irrigation canals or by designing schedules for draining.

”The benefits achieved by limiting the greenhouse emissions lie with the global society and not with the poor farmers who probably are more concerned with growing enough food for their children. Therefore, there is a need for institutional support and help for the implementation,” he says.

Read the original news in Danish here.

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