Researchers at the Brazilian Center for Research in Energy and Materials (CNPEM), the Brazilian Agricultural Research Corporation (EMBRAPA), and several other educational and research institutions spent two days defining the scientific methodology for groundbreaking work to explore fundamental questions related to soil cohesion, a phenomenon in Brazil’s coastal tablelands region which is not yet clearly understood.

Cohesive soils are formed from sediment, and are known for becoming extremely hard when they dry out. This phenomenon is difficult to manage and occurs naturally over 100,000 square kilometers in an area extending from the state of Rio de Janeiro to Amapá. The cohesive layer generally occurs 30–70 centimeters below the surface and affects root growth and absorption of water and nutrients. This issue has caused problems for land use, management, and conservation, especially in Northeastern Brazil, with significant impacts on agricultural productivity.

The 1st CNPEM-EMBRAPA Workshop on Cohesive Soils was planned to bring together a variety of competencies from the two institutions to tackle this major strategic problem that affects agriculture and the environment. It is an unprecedented initiative at CNPEM, which is home to Sirius, one of only three state-of-the-art synchrotron light sources in the world and a cutting-edge scientific resource that can make the difference in investigating the microscopic mechanisms related to soil cohesion.

Sirius, along with the rest of the CNPEM facilities, is open to the scientific and business communities. In line with established international practice, researchers interested in using the beamlines at Sirius present research proposals which are evaluated by their peers each semester. The most scientifically compelling proposals submitted each cycle (regardless of topic) are selected and scheduled for experiment time.

Example of microtomography carried out by researcher Talita Ferreira in a study aimed at understanding water movement within soil. The same procedure can be used to understand the behavior observed in cohesive soils after cycles of wetting and drying. The animation shows 2D slices (in gray) along a 3D tomography of a soil sample. The soil pores are represented in blue and the solid part in brown. At the end, the pore with the largest volume is highlighted in yellow, and one can visualize the water injection simulation into this pore. The lines represent the paths taken by the water and the colors represent the variation in fluid velocity in different parts of the pore. (DOI https://doi.org/10.1016/j.jhydrol.2022.128024).

New model: mission-driven 

The initiative of this task force, which is working to advance fundamental knowledge and obtain innovative solutions for managing cohesive soils, is located within a new model for accessing the facilities at Sirius, with allocation of various experimental stations and interdisciplinary research teams that can address challenges and missions from different perspectives. 

By choosing a mission focused on a significant challenge in the area of soil science that involves known specialists in Brazilian soil science to explore various approaches and hypotheses, CNPEM is working to involve the scientific community in a new, more collaborative model for using the synchrotron light technologies at Sirius in order to accelerate the development of solutions for the large strategic challenges Brazil faces.

“It was very interesting to observe the evolution of ideas from this group of specialists in various subdisciplines of soil science, agronomy, physics, materials science, chemistry, and other areas as the workshop unfolded. The discussions ultimately led to a unified plan of investigation that involved contributions from everyone, from sampling of cohesive soils to collecting and interpreting the synchrotron data,” explains CNPEM researcher Dean Hesterberg, who was responsible for organizing the event. 

The efforts attracted cooperation from researchers at various research and teaching institutions across Brazil, such as Santa Cruz State University (UESC), the Federal University Rural of Pernambuco (UFRPE), the Federal University of Paraná (UFPR), the Federal University of Ceará (UFCE), Ponta Grossa State University (UEPG), and the University of São Paulo (USP-ESALQ). 

The work

The meeting led to the development of a work plan that includes field testing and collection of samples, which will be brought to CNPEM for analyses using the Sirius beamlines. The discussions identified the potential to use resources in at least five of the experimental stations at Sirius, namely the Carnaúba, Imbuia, Paineira, Cateretê, and Mogno beamlines. The samples will be analyzed using microtomography, nanotomography, and high-resolution crystallography, among other experimental techniques using synchrotron light. 

The experiments are planned to be conducted by July, and within a period of approximately six months the group will meet again to discuss the results and define the next steps. 

“Science is made up of uncertainties, for this reason we are testing a new model of scientific work to address major problems in the country. This workshop was just the beginning, since we are in the phase of asking why these cohesive soils occur. Only afterwards will we investigate potential solutions, and then how we should address other practical issues like the financial sustainability of each of the solutions we find,” says Harry Westfahl Jr., director of the Brazilian Synchrotron Light National Laboratory. 

According to José Coelho de Araújo Filho, a researcher at the Recife Research and Development Unit of Embrapa Soils, “the multidisciplinary nature of this initiative gave us a better understanding of how to deal with the cause of the problem, sharing the various responsibilities and strategies to arrive at conclusions about the causes. This joint vision provided us with a better analysis of the problem.” 

“We hope that this first initiative, focused on using the cutting-edge resources at CNPEM and intensive work by a group of specialists from various areas focused on one strategic mission, will accelerate results and solutions for large-scale problems in all kinds of knowledge areas. We want to show how Sirius is an accessible, open, and useful resource for solving the real problems that affect Brazilian society. The major answers are constructed collectively, and for this reason it is essential to have an organization like EMBRAPA as a partner to formulate better questions and answers in this great challenge,” says CNPEM Director General Antonio José Roque da Silva.

About CNPEM

A sophisticated and effervescent environment for research and development, unique in Brazil and present in few scientific centers in the world, the Brazilian Center for Research in Energy and Materials (CNPEM) is a private non-profit organization, under the supervision of the Ministry of Science, Technology and Innovation (MCTI). The Center operates four National Laboratories and is the birthplace of the most complex project in Brazilian science – Sirius – one of the most advanced synchrotron light sources in the world. CNPEM brings together highly specialized multi-thematic teams, globally competitive laboratory infrastructures open to the scientific community, strategic lines of investigation, innovative projects in partnership with the productive sector and training of researchers and students. The Center is an environment driven by the search for solutions with impact in the areas of Health, Energy and Renewable Materials, Agro-environment, and Quantum Technologies. As of 2022, with the support of the Ministry of Education (MEC), CNPEM expanded its activities with the opening of the Ilum School of Science. The interdisciplinary higher course in Science, Technology and Innovation adopts innovative proposals with the aim of offering excellent, free, full-time training with immersion in the CNPEM research environment. Through the CNPEM 360 Platform, it is possible to explore, in a virtual and immersive way, the main environments and activities of the Center, visit: https://pages.cnpem.br/cnpem360/.