Summary 
High-density olive groves capture significantly more carbon dioxide per hectare than traditionally planted groves, according to the GO Olive Carbon Balance project’s initial results. Researchers compared different olive grove management models and planting densities in Andalusia and Castilla-La Mancha to assess carbon sequestration rates, finding that higher planting densities exhibited the highest carbon capture rates.
The first results of the GO Olive Carbon Balance project show that high-density olive groves capture significantly more carbon dioxide per hectare than traditionally planted groves.
Researchers from the Spanish Association of Olive Growing Municipalities (AEMO) AgroecoliveLab and the University of Jaén compared different olive grove management models and planting densities across several farms operated by producers and cooperatives in Andalusia and Castilla-La Mancha. The goal was to assess how effectively each system sequesters carbon dioxide.
The researchers confirmed that all types of olive groves capture carbon dioxide, storing it in their wood. However, they found that “olive groves with higher planting densities exhibit the highest carbon capture rates.”
High-density groves, defined as those planted with between 900 and 1,400 trees per hectare, captured an average of 6.4 tons of carbon dioxide per hectare per year.
The most productive site in the study was a high-density olive grove in Lora del Río, in the province of Seville, which captured nearly 12 tons of carbon dioxide per hectare annually.
By comparison, traditional olive groves with 100 to 150 trees per hectare sequestered an average of 1.2 tons of carbon dioxide per hectare per year. Medium-density groves, with 200 to 300 trees per hectare, captured an average of 1.1 tons.
Despite having 1,800 to 2,000 trees per hectare, the super-high-density groves analyzed in the study captured an average of 2.2 tons of carbon dioxide per hectare annually. The researchers attributed the lower sequestration rates to the trees’ younger age.
“These amounts are similar to or even greater than the CO2 equivalent emitted in field operations,” wrote Roberto García, a professor of animal and plant biology at the University of Jaén, in a blog post. “In practical terms, this means that olive groves can not only approach climate neutrality but can also actively contribute to mitigating climate change.”
In the subsequent phases of the project, researchers will analyze how soil management, pruning, fertilization, phytosanitary treatments and cover crop cultivation influence carbon sequestration in olive groves.
Once a scientific framework is established to determine the carbon balance of different olive grove systems and planting densities, the team plans to develop an algorithm to calculate carbon balances and an application to validate carbon credits.
The researchers also expect the findings to inform best practices for increasing carbon sequestration in olive groves.
The GO Olive Carbon Balance project is one of several initiatives examining how olive groves sequester carbon and how this capacity could be measured and monetized through carbon credits.
In May, the International Olive Council launched a pilot project seeking volunteer producers to calculate how much carbon dioxide their groves sequester using an online tool to generate carbon credits.
Meanwhile, a separate group of Andalusian researchers behind the C‑Olivar project studied how cultivation practices affect carbon sequestration.
They found significant differences between management systems, with sequestration ranging from 0.6 to 2.6 tons of carbon dioxide equivalent per hectare. Groves with the highest sequestration levels typically featured ground cover and healthier soils.
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