San Jose, 26 January 2023 (TDI): In Costa Rica, scientists are looking to adopt new ways to use fertilizers to reduce the emissions of Greenhouse Gases (GHGs).

The use of land and agricultural practices, contribute to about a quarter of the greenhouse gases that cause global warming. 

The International Atomic Energy Association (IAEA) and the Food and Agriculture Organization of the United Nations (FAO), researchers at the country’s National Rice Corporation (CONARROZ) and Environmental Pollution Research Centre (CICA) are employing isotopic techniques to establish best practices regarding the use of nitrogen fertilizers in rice plantations.

Fertilizers and Greenhouse Gases

These gases include nitrous oxide. When it is released it warms the atmosphere 265 times more than carbon dioxide does.

It is released by different biological processes from nitrogen. It is a nutrient for plants naturally present in soil and added via chemical and organic fertilizers. 

The excess application of such fertilizers leads to the release of GHGs into the atmosphere, contributing to climate change.

For the production of rice, scientists are looking for measures to reduce GHG, while improving plant productivity and farmers’ livelihoods through climate-smart agriculture practices. 

In traditional practice, farmers use nitrogen fertilizers to improve their crops. With this they are contributing to the emission of GHG, said Mohammed Zaman, FAO/IAEA Soil Scientist. 

“A plant needs seventeen types of nutrients, the most important of which is nitrogen,” said Mohammed Zaman, “It’s traditional that farmers use nitrogen fertilizers to improve their crops.

However, they may be adding more nitrogen than what a plant can absorb. This not only generates extra emissions of nitrous oxide but also makes the plant less productive and impacts farmers’ income.”

New Research

CONARROZ and CICA are using isotopic techniques to find out how much fertilizer is needed to optimize rice. Moreover, when to apply the fertilizer during the rice’s life cycle and the ideal chemical composition of fertilizer for rice. 

“We’re looking to find a fertilizer combination that will maximize plant productivity while keeping nitrous oxide and ammonia emissions to a minimum,” said Ana Gabriela Pérez Castillo, a researcher at CICA. 

Greenhouse Gases
Ana Gabriela Pérez, coordinator of the University of Costa Rica’s National Reference Laboratory for Greenhouse Gases and Carbon Sequestration

She said we need reliable data on emissions, she is conducting experiments using the nitrogen-15 isotope technique to trace the movement & origin of nitrous oxide emissions & determine whether they are produced from nitrogen in fertilizers or the soil.

This would help the farmers to use fertilizers in a more optimal way to protect the environment. CICA has long employed the nitrogen-15 isotope technique in its efforts to study how to mitigate GHG emissions in agriculture. 

CICA and IAEA are collaborating since 2006 on this project. CICA is transferring knowledge and expertise with IAEA. CICA has also trained 2000 scientists for this project.