17 April 2024

Return of microbes certifies soil restoration in Brazil


A study highlights the recovery of microbial diversity in regenerated semi-arid areas in Brazil. Thus confirming the validity of soil regeneration techniques

by Matteo Cavallito


Regeneration of degraded lands in Brazil is reportedly producing promising results from the restoration of original microbial communities and the related ecosystem services they provide. This is supported by a study published in the Journal of Environmental Management.

The investigation, by a team of researchers from four different universities-São Paulo (USP), Piauí (UFPI), Ceará (UFC) and Pernambuco (UFAPE)-looked at 18 previous research studies that focused on the Caatinga forest in the eastern part of the country. Characterized by semi-arid biomes, the area is one of the richest in the world in terms of biodiversity.

A region at risk

Climate change and human activities, however, threaten the balance of this environment. “Land desertification poses a significant challenge in the Brazilian semiarid region, encompassing a substantial portion of the country,” the study states. “Within this region, the detrimental effects of human activities, particularly unsuitable anthropic actions, have resulted in diminished vegetation cover and an accelerated rate of soil erosion.”

According to the authors, in particular, the conversion of forests to pasture land has contributed to the process of land desertification. Resulting, they explain, in “significant losses of soil organic matter and microbial diversity.”

To solve the problem, the research still notes, various restoration measures have been implemented over the years. These include practices such as various grazing restrictions, the use of cover crops and terracing to control erosion. Such actions would appear to have been successful. Ensuring the recovery of soil microbial properties and biodiversity and increasing crop yields.

Biodiversity has been restored

“We set out to understand the soil microbiome and its functions in order to identify tools that can help restore degraded areas in the semi-arid region,” Lucas William Mendes, co-author of the study, told the FAPESP news agency in an article authored by Luciana Constantino.

“We found that restoration techniques have led to a return of microbial diversity,” He added. And, therefore “a resumption of ecosystem services and functions similar to what they were naturally.”

The authors, the paper explains, used some molecular survey techniques such as metagenomics and metatranscriptomics to measure and assess the level of restoration of the soil microbiome. Some areas were regenerated with new vegetation cover, which provided new forage for the livestock. “With plant cover changing soil chemistry, improvements in pasture were sufficient to support an increase in head of cattle per hectare and in productivity,” Mendes added.

Microbes have a crucial role

The study again highlighted the key role played by microbes such as bacteria, fungi and archaea in influencing nutrient cycling. As well as the decomposition of organic matter, greenhouse gas emissions and, ultimately, plant health. In this scenario, Mendes says, “By understanding how some microorganisms live in drought-ridden areas and contribute to plant growth there, we can discover novel inoculants for use in developing vegetation in semi-arid regions.”

This kind of research, co-author Erika Valente de Medeiros points out, highlights “the interconnectedness between ecosystem health, soil microbiome diversity and human wellbeing.” The findings, the authors further explain, can provide important knowledge for policy makers to design sustainable development strategies and counter desertification.