Healthy pastures can enhance carbon sequestration and storage

A group of scientists linked to the Research Center for Innovation in Greenhouse Gases (RCGI) seeks to identify the best alternatives to recover the millions of hectares of pastures in the country that show some degree of degradation. The researchers also seek to understand how this action can contribute to Brazil meeting the climate goals assumed in the Paris Agreement.

RCGI is an Engineering Research Center (CPE) constituted by FAPESP and Shell at the Polytechnic School of the University of São Paulo (Poli-USP).

“In the Paris Agreement, during the United Nations Conference on Climate Change [COP21], in 2015, the country committed, among other measures, to recover 15 million hectares of degraded pastures, which has already happened. But this is a low number, if we consider that approximately 50% of the pastures remain with some degree of degradation”, says agronomist Carlos Eduardo Pellegrino Cerri, project coordinator and professor at the Luiz de Queiroz College of Agriculture (Esalq-USP) .

For Cerri, well-managed pastures can sequester and store carbon in the soil. “We want to find out how high this can go,” she explains. This information, says the researcher, can serve as input for the development of new public policies that encourage the recovery of pastures, for example. Or contribute to the evaluation of existing initiatives.

At the moment, the team, made up of ten researchers and 20 undergraduate students from various parts of Brazil, as well as consultants from the United States and United Kingdom, is dedicated to fieldwork. “So far we have visited 12 locations in the Northeast region, such as the municipality of Limoeiro do Norte, in Ceará. Soon we will head to the states of Rondônia, Mato Grosso and Tocantins”, says the professor. In total, 47 trips are planned across the country. “We will visit pastures in all Brazilian regions and with varying degrees of conservation.”

According to Cerri, the idea is to discover at least a couple of pastures in each location, one of them healthy and the other degraded. “The idea is to compare these two situations. From samples from a well-kept pasture, we can know, for example, what is the maximum carbon accumulation possible to obtain in that region with the adoption of good management practices.”

Everywhere, researchers collect samples of soil, greenhouse gases and vegetation. This material then goes to the laboratory to be analyzed.

After this phase, researchers will apply modeling to jointly evaluate the data collected through the available bibliography and also through the field study. “We are going to test several scenarios on the computer, taking into account the characteristics of each region of Brazil”, says the professor.