Conventional strategies to increase cacao output often involve expanding plantations by clearing tropical forests, thereby replacing complex, carbon-rich ecosystems with monoculture farms. This practice contributes to biodiversity loss and carbon emissions. However, an alternative path exists: enhancing yields on the already cultivated land. Current average yields for cacao hover around 480 kilograms per hectare, yet theoretical potential suggests these figures could be amplified manifold. Unlocking this latent productivity requires careful intervention and soil management that align with both economic and ecological goals.

Steeley’s pioneering research, soon to be unveiled at the 2026 European Geosciences Union (EGU) General Assembly, investigates the application of enhanced rock weathering (ERW) as a soil amendment technique to boost soil fertility and increase cacao yield in the Atlantic Rainforest region of Brazil. This ecosystem, fragmented and degraded over years of anthropogenic pressure, presents a unique challenge for sustainable agriculture. The research focuses on two distinct cacao cultivation systems: commercial farms that reforest degraded pasturelands with cacao interspersed among shade trees, and the traditional cabruca system, which integrates cacao trees within the remaining native forest understory, thereby conserving more biodiversity at the expense of yield.

In intact tropical forests, nutrient cycling is a finely balanced process. Roots absorb nutrients from the soil while decaying organic matter replenishes it, maintaining soil fertility. When forests are cleared, this cycle is disrupted. Tropical soils, characterized by intense rainfall and warmth, naturally exhibit low nutrient retention due to rapid leaching and acidification. As acidity rises, essential nutrients become less bioavailable and toxic elements, including aluminum and cadmium, become more soluble, hampering plant growth and yield. Such conditions often lead to declining cacao productivity after 20 years or so of cultivation.

Enhanced rock weathering introduces a compelling approach to counteract these soil limitations. By applying finely ground basalt dust—specifically andesitic basalt sourced locally in Brazil—the technique accelerates natural silicate mineral weathering processes. As the rock dust dissolves, it neutralizes soil acidity and releases base cations such as calcium, magnesium, and potassium, essential for plant nutrition. Moreover, the process captures atmospheric carbon dioxide, converting it into stable soil carbonate minerals, thereby offering a dual benefit of mitigation and adaptation in agricultural landscapes.

Preliminary results from the first two years of Steeley and her colleagues’ three-year study reveal significant soil improvements, particularly in commercial cacao plantations where reforestation occurs on degraded pasturelands. These ameliorations suggest an opportunity to reconnect fragmented rainforest patches while enhancing agricultural productivity. The cabruca systems, despite their lower productivity, demonstrate promising carbon sequestration potential through ERW. Steeley’s group has developed novel quantification methods to determine the extent of rock dust weathering, enabling accurate calculation of carbon sequestered within these soils.

Intriguingly, early data indicate that cabruca soils may sequester more atmospheric CO₂ than commercial farms through enhanced rock weathering, implying that smallholder farmers engaged in traditional agroforestry could monetize carbon credits. This potential creates a unique incentive structure whereby environmental stewardship and economic gain could synergize, supporting rural livelihoods and fostering sustainable land management. Given that most cacao production occurs on farms smaller than 50 hectares, such co-benefits could have transformative impacts within local communities.

Collaboration with local farmers and agronomists lies at the heart of this research. Steeley emphasizes the collective nature of the endeavor, highlighting farmer enthusiasm for innovative practices that safeguard their income while enhancing ecological sustainability. This inclusive approach ensures that scientific advancements translate into practical, scalable solutions tailored to the socio-economic realities of cacao-producing regions.

The challenges of tropical soil fertility are compounded by climatic factors, but enhanced rock weathering offers a geochemical pathway to rehabilitate degraded landscapes. By increasing soil pH and nutrient availability, this method holds promise for reversing yield declines typical in long-term cacao cultivation. Sustainability in cocoa production, therefore, does not merely hinge on avoiding deforestation but also on revitalizing existing farmlands through scientifically informed interventions.

At the upcoming EGU General Assembly 2026, Steeley will present these compelling findings during Session SSS5.6 on May 5, offering insights into how geoscientific advances can contribute to sustainable agriculture and climate mitigation. Her work bridges multiple disciplines, from soil chemistry and geochemistry to agroforestry and carbon cycle science, exemplifying integrated approaches necessary to address complex environmental challenges.

The implications extend beyond cocoa farming. Enhanced rock weathering presents a scalable, nature-based solution applicable to various tropical and subtropical agroecosystems struggling with soil acidification and nutrient depletion. It also aligns with global efforts to achieve carbon neutrality by enhancing terrestrial carbon sinks while sustaining food security.

In sum, Steeley’s research underscores a paradigm shift in tropical agriculture wherein ancient geological processes are harnessed to forge resilient, productive, and carbon-beneficial farming systems. As demand for cacao and other tropical commodities intensifies, such innovations offer a beacon of hope for conserving biodiversity, mitigating climate change, and uplifting rural livelihoods, all crucial goals in the Anthropocene epoch.

Subject of Research: Enhanced rock weathering for improving soil fertility and carbon sequestration in cacao agroforestry systems.

Article Title: Harnessing Enhanced Rock Weathering to Sustainably Boost Cacao Yields and Carbon Capture in Brazil’s Atlantic Rainforest.

News Publication Date: Not specified.

Web References: European Geosciences Union General Assembly 2026 session page: https://meetingorganizer.copernicus.org/EGU26/session/57859

Image Credits: Steeley et al., 2025

Keywords: Enhanced rock weathering, cacao yield, soil fertility, agroforestry, Atlantic Rainforest, carbon sequestration, tropical soils, basalt dust, soil acidification, agroecology, sustainable agriculture, climate mitigation

The research presents a detailed risk assessment aimed at discerning how pesticide residues from agricultural land are distributed in the environment and, crucially, how they make their way into the human population. The researchers utilized an extensive framework, advising that vulnerability assessments of human exposure to these residues should consider a tapestry of pathways, including dietary intake, water contamination, and even direct contact during agricultural processes. Each pathway delineates a narrative of potential health repercussions, emphasizing the importance of awareness in agricultural practices.

Drawing on empirical data gleaned from the vibrant yet fragile ecosystems of Costa Rica, the study notably outlines the critical role of agricultural techniques and the regulatory environment surrounding pesticide use. The authors collected samples from various water sources and agricultural products, assessing residue levels to offer a comprehensive analysis of exposure risks. This evidence-based approach elucidates the reality that, while pesticides can enhance crop yield, their residues pose significant threats to both ecological integrity and human health.

One of the study’s significant revelations is the intricacy involved in how pesticide residues interact with ecological systems. These chemicals do not merely reside on crops; they leach into the soil and waterways, establishing a web of exposure opportunities that can extend far beyond the immediate vicinity of agricultural fields. Thus, local populations, particularly those dependent on these landscapes for their livelihood, find themselves in a precarious position, facing potential toxicity without direct awareness of the risks.

Moreover, the assessment highlights the socio-economic ramifications of pesticide exposure. Many farmers, often lacking adequate resources or knowledge about safe pesticide application, may expose themselves and their families to harmful residues. This situation is particularly notable in regions where education on agricultural practices is insufficient. The necessity for improved educational outreach, better regulatory frameworks, and accessible information is paramount to safeguard public health and environmental conservation.

The patterns of pesticide usage in Costa Rica reflect a larger global problem confronted by agricultural economies worldwide: how to balance pest control with public health. As agriculture modernizes, the stakes intensify around the practices put in place. The authors stress the importance of integrating organic farming practices as viable alternatives that can diminish reliance on harmful chemicals, resulting in healthier ecosystems and communities.

Additionally, the implications of the study resonate with emerging global trends towards sustainability. As the discourse around climate change and environmental degradation becomes more pronounced, it is critical to reevaluate our agricultural choices. The research findings can serve as a catalyst for broader discussions about sustainable agriculture in tropical regions, emphasizing the need to establish agricultural frameworks that prioritize both crop health and human well-being.

This pressing issue is not confined to the pages of academic journals; it demands active engagement from policymakers, agricultural experts, and communities alike. Stakeholder collaboration is essential for harmonizing policies that regulate pesticide use while promoting agricultural innovation. By adopting multifaceted strategies, including the use of biopesticides and agroecological principles, the agricultural sector can transform and pursue a more sustainable trajectory.

Furthermore, the research acts as a clarion call for governments and institutions to establish stricter regulations on pesticide usage. There is an urgent need for policies that can mitigate exposure risks, particularly in vulnerable communities. Strategies to monitor and regulate pesticide application must prioritize human and environmental health, ensuring that agricultural practices foster resilience rather than risk.

As health professionals and environmental scientists continue to underscore the potential hazards of pesticides, public health campaigns must also rise to the occasion. Educating local populations about safe agricultural practices and risks associated with pesticide exposure can empower communities to make informed decisions. When communities are well-informed, they can advocate for better regulations and, by extension, healthier living conditions.

Looking ahead, the researchers assert that continuous monitoring of pesticide residues and studying their long-term health impacts are crucial for developing effective public health strategies. The study is not merely a snapshot in time; it serves as a foundational framework upon which future research can build. With ongoing research, the aim is to create more targeted public health interventions that can inform agricultural practices globally.

In conclusion, this comprehensive assessment sheds light on an intricate relationship between pesticide use, human health, and environmental sustainability. The findings from Costa Rica echo a universal challenge faced by mankind: the need for sustainable agricultural practices that protect both our health and the planet. As awareness grows, it is essential that these discussions permeate public consciousness, effecting change that fosters both ecological balance and human health prosperity.

Subject of Research: Human health risk assessment related to pesticide residues in tropical agroecosystems.

Article Title: Multiple exposure pathways to pesticide residues in tropical agroecosystems: A human health risk assessment in Costa Rica.

Article References: Montiel-Mora, J.R., Pérez-Rojas, G., Brenes-Alfaro, L. et al. Multiple exposure pathways to pesticide residues in tropical agroecosystems: A human health risk assessment in Costa Rica.
Environ Monit Assess 198, 47 (2026). https://doi.org/10.1007/s10661-025-14869-8

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s10661-025-14869-8

Keywords: Pesticide residues, human health, risk assessment, agroecosystems, Costa Rica, sustainable agriculture, environmental health.