World Soil Day: Reviving South Africa’s soils for a sustainable future

Soil degradation poses a major threat to South Africa’s agriculture, with up to 12 million hectares severely eroded and an estimated 10%-20% of farmland affected. More broadly, studies suggest that up to 60% of the country’s land is degraded. Globally, declining soil health undermines water security, biodiversity, and the long-term productivity that farmers rely on.

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Healthy soils are crucial not just for crop yields but for supporting rural livelihoods, food systems, and trade. While agriculture contributes a modest share of the national GDP, its influence extends far beyond production, sustaining communities and ensuring global food security.

World Soil Day, celebrated on December 5, highlights the vital role of soil in human well-being and promotes stronger stewardship through international awareness campaigns.

Regenerative practices for stronger soils

Restoring soil function is essential for climate resilience and sustainable agriculture worldwide. Many farmers are adopting regenerative practices that improve plant–soil interactions over time.

Among these tools are natural biostimulants derived from seaweed, which have been studied for their compatibility with beneficial soil microbes and their potential to support root development, stress tolerance and crop establishment when used alongside good agronomy.

Laboratory work on extracts of Ecklonia maxima, the South African kelp species used in Kelpak’s natural biostimulants, has shown promising results.

In controlled trials, beneficial organisms such as Trichoderma (a fungus that protects roots against harmful pathogens) and rhizobia (nitrogen-fixing bacteria) showed their strongest viability when exposed to low concentrations of the extracts for short periods. This suggests that natural extracts can work in harmony with microbial inoculants under the right conditions.

A separate Polish study by Kelpak on Trichoderma harzianum and Verticillium dahliae found that while the extract supported the growth of beneficial fungi, it simultaneously slowed the sporulation of harmful pathogens. This is an example of the selective effects that impact the soil microbiome.

"World Soil Day is a reminder that agro-ecosystems start with living soil," says Linda Greyling, head of technical support at Kelpak. "Biostimulants are not a silver bullet.

"They are most effective when used alongside sound practices such as mulching, diversified rotations and careful traffic management. Our focus is on generating practical evidence that helps farmers apply natural tools where they make agronomic sense, season after season."

According to Greyling, long-term benefits associated with natural biostimulants include:

• Supporting beneficial microbes such as Trichoderma and rhizobia to survive and remain active.
• Promoting the growth of beneficial fungi while slowing certain disease-causing species.
• Strengthening root growth through naturally occurring plant hormones.
• Improving plant-level tolerance to abiotic stress such as heat or drought, when paired with broader conservation practices.
• Being used effectively alongside seed treatments or inoculants when applied according to guidance.

Healthy soils are living, dynamic systems, and safeguarding them is essential for resilient agriculture worldwide.

By integrating natural biostimulants thoughtfully with regenerative practices, farmers can rebuild soil function, enhance crop resilience, and take meaningful steps toward a sustainable agricultural future rooted in living soil.