Stopping methane by saving water
by Dubi Raz
More than 3.5 billion people depend on rice as a staple food and pre-dominant calorie source. That is one fifth of the world’s population – and the demand for rice is constantly growing. However, rice cultivation has a significant impact on the environment. That is why we at Netafim have taken up the task of helping smallholders to grow rice in harmony with nature – drop by drop.
Global Agronomy Director at Netafim
For thousands of years, smallholders have traditionally cultivated rice in puddled fields that are kept flooded with 5-10 centimeters of water throughout the growing season. Today, these puddled fields account for 12% of the global crop acreage. This makes rice one of the most water-guzzling crops, consuming more than half of all developed fresh water resources.
In other words, it takes 3,000–5,000 liters of water to produce 1 kilogram of rice. Considering the increasing scarcity of water due to climate change, every drop of water counts when it comes to helping smallholders unlock their full agronomic potential and cultivate enough to feed a growing world population.
At the same time, paddy rice cultivation is also responsible for environmental degradation through producing up to 10% of global methane gas emissions. Stagnant water and anaerobic decomposition of organic matter are the major factors contributing to the release of methane from rice fields into the atmosphere. Moreover, nitrous oxide is another gas produced by soil microbes. According to the US-based advocacy group Environmental Defense Fund (EDF), methane and nitrous oxide emissions from rice farms could have the same short-term warming impact as about 600 coal plants (1,900 MMT per year CO2e100).
Bearing in mind the global warming crisis, can we afford to have more greenhouse gas emissions? For me the question lies in how we can significantly reduce greenhouse emissions from rice paddy fields without compromising on the yields and earnings of millions of rice smallholders who depend on it. To provide an answer, my team and I had to challenge a 5,000-year-old assumption – namely that rice grows best anaerobically. That might be a bit controversial, as this form of rice cultivation has proved successful over time. Nevertheless, it helped us to completely rethink irrigation and take the next step towards the future of rice cultivation.
Many studies have shown that some rice varieties can be successfully grown under much drier conditions than traditional methods – with reduced methane emissions and yield losses. In other words, our drip irrigation system perfected specifically for rice is more than just a technological package. It represents a paradigm shift in the way rice production is understood and practiced based on the biological potential.
Our own studies conducted in the southern Indian state of Tamil Nadu for example have shown that flood-irrigated rice paddies produce up to 2.9 milligrams of nitrous oxides per square meter per day. These same paddies irrigated by our drip irrigation system only produce up to 0.5 milligrams of nitrous oxides, with 70% less water needed. But of course, drip irrigation is not only important to water the rice plants. It is also essential for the effective and sustainable use of fertilizer. Through drip irrigation the plants can absorb water and nutrients with no risk of nitrates from fertilizers seeping into the groundwater and surrounding environments, which also reduces greenhouse gas emissions. And that’s not all. Rice grown using drip irrigation also outperforms traditional methods in terms of production costs, time, labor efficiency, and yields.
Additionally, by using our seeding machine smallholders no longer need to wait for seedlings to sprout before sowing them. They can directly sow the seeds, which saves them even more time and labor for high-quality crops.
Learn more about how rice smallholder Henry Cambangay is farming for a better life
I believe that one drop of water is really more than you think. It is full of new opportunities for efficient, sustainable, and climate-resilient agriculture. It excites me to know that with our drip irrigation technology, we as a Better Life Farming partner are able to make a significant contribution to realizing our purpose as an alliance.
Better Life Farming is all about empowering individual smallholders to farm for a better life and help to grow food for the world. It drives me to know that we can support rice smallholders to sustainably grow more with less and I am very much looking forward to equipping all our smallholder rice farmers across the world with our drip irrigation technology in the near future.