By integrating drip and micro irrigation technologies within the world’s rice paddies, farmers can simultaneously contribution to the international struggle against greenhouse gas emissions and increase their crop yields, according to Israeli irrigation giant Netafim.
In conjunction with the Tamil Nadu Agricultural University, Netafim has long been studying rice crops in India, finding that "flooding" irrigation – which is still practiced heavily around the world – is causing "tremendous greenhouse gas emissions compared to the more economical drip irrigation."
By employing drip irrigation to both water and fertilize the paddies, the company said it has significantly reduced the amount of greenhouse gases released and can prevent the penetration of nitrates into groundwater.
“We’re talking about huge amounts of gas emissions,” Dubi Raz, chief agronomist for Netafim, told The Jerusalem Post
Established in 1965, Netafim originated in the drip irrigation discovery of water engineer Simcha Blass. While still based in Israel, the company now has subsidiaries in countries on every continent around the world, excluding Antarctica.
The dominant greenhouse gases generated in rice growth are methane and nitrous oxide. Methanogens produce methane gas under anaerobic conditions in the rice fields, while nitrifying and denitrifying bacteria that operate under anoxic conditions generate nitrous oxides.
In rice paddies irrigated by flooding, Netafim researchers in the southern Tamil Nadu state found that about 2.9 milligrams of nitrous oxides are generated per square meter each day. Whereas, those paddies irrigated by drip methods only produce about 0.5 milligrams of nitrous oxides per square meter daily, Raz explained.
Not only is it important to use drip irrigation technologies to water the rice plants, but it is also critical to use these methods for fertilization, he stressed.
This way, the plants can absorb all of the water and nutrients they need without risking downward seepage of nitrates from fertilizers into the groundwater and surrounding environments – a phenomenon that has caused heavy damage globally in places such as the Great Barrier Reef, Raz explained.
“The plant will take everything and nothing will go down,” he said.
Employing drip irrigation, he added, is “much friendlier to the environment.”
A similar study about the relationship of traditional rice field cultivation and greenhouse gas emissions occurred in Thailand, at King Mogkut's University of Technology in Thonburi in 2005. In that study, researchers looked at various options for reducing the enormous greenhouse gas emissions emanating from the paddies, such as draining the flooded fields and altering fertilizer application methods.
The American study, presented to the Pew Center on Global Climate Change in 2006 by researchers from Coloardo State University, Montana State University and the National Renewable Energy Laboratory, explored the production of greenhouse gases in the US agricultural sector as a whole. As in the other studies, these researchers also conclude that a more efficient use of nitrogen can reduce nutrient runoff and improve water quality in both the ground and surface waters.
Because rice has been grown for 5,000 years using flood irrigation, it is somewhat of a challenge to prove the advantages of revolutionizing the watering technologies of a global industry.
Nonetheless, Raz said that Netafim’s research teams have now reached the point at which they are yielding three times the amount of rice on their drip irrigated commercial-sized plots than similarly sized flooded fields. They are currently in the process of launching a full-fledged commercial effort among local Indian farmers, in conjunction with the Tamil Nadu Agricultural University and the government, Raz explained.
“If in the end it is not commercial, people will not invest,” Raz said. “We have to show economically wise people that they will get back their investment, that there are high yields.”