Field trials by WorldVeg on okra in Taiwan have demonstrated the potential of biochar to transform vegetable production.
Biochar is a charcoal-like material produced applied to soils to improve fertility, increase carbon storage, and enhance overall soil health.
According to WorldVeg, an application rate of 30 tonnes per hectare –with mineral or organic fertiliser – improved plant growth and boosted yields by 35 per cent and 41 per cent respectively, compared to mineral and organic fertilisers without biochar.
It also significantly improved nitrogen use efficiency and reduced GHG emissions.
Crop research showed that the use of biochar can reduce nitrous oxide emissions by 39 per cent on average, although the evidence from vegetable systems is limited, said WorldVeg.
Several benefits for soil
Furthermore, biochar applications improved several key aspects of soil health.
In addition, biochar applications in the okra fields:
They reduced bulk density, which enhances aeration and limits compaction, supporting better root growth and water infiltration.
Biochar also increased the proportion of small soil aggregates – tiny clumps of sand, silt, clay, organic matter, and microbial substances that help retain carbon, water, and nutrients,
Biochar boosted the overall soil carbon sink and reduced nitrous oxide emissions from the soil.
Meanwhile, the trial showed that it did not have a negative impact on the diversity of the soil microbiome.
“It’s encouraging and exciting to see that solutions such as biochar have multiple wins for vegetable production – from improved soil health and increased productivity to reduced greenhouse gas emissions,” said Lukas Pawera, agronomist and agroecologist at WorldVeg, who led the okra trials.
The research signals that integrating biochar into vegetable production systems could be a game-changer for growers seeking to improve yields while reducing environmental impacts.
By enhancing soil fertility, optimising nitrogen use, and lowering greenhouse gas emissions, biochar offers a practical solution for climate-smart horticulture, aligning productivity with sustainability.
Beyond biochar
Urban populations rely on vegetables, but farmers face growing climate-related challenges, while conventional agriculture contributes heavily to greenhouse gas emissions.
To meet these challenges, WorldVeg has been trialling vegetable production using a range of agroecological approaches recognised by the Intergovernmental Panel on Climate Change (IPCC).
Biochar is just one component of a broader suite of regenerative and agroecological practices and WorldVeg is also testing various others.
The organisation is also exploring complementary strategies such as using black soldier flies to turn urban food waste into nutrient-rich frass, which can be used as fertiliser.
It is also exploring vermicomposting and use of bioslurry, reducing tillage intensity for vegetables, testing organic and biodegradable mulch, and identifying options for soil and climate-friendly crop diversification.
Together, these practices aim to build healthier, more resilient soils that can support sustainable vegetable production over the long term.
Pawera concluced: “Building healthy soils today means investing in the resilience of tomorrow. That means more sustainable vegetable production and healthier consumers – wherever they may be,”
