BIOCHAR is a carbon-rich material produced from organic biomass through pyrolysis – heating in low-oxygen conditions. It is increasingly recognised as a practical nature-based solution because it addresses two pressing global challenges at once: reducing greenhouse gas concentrations and restoring degraded soils.
As climate change accelerates and agricultural systems face mounting pressure from drought, erosion, and nutrient loss, biochar offers a pathway that combines long-term carbon storage with improved soil performance and resilience.
The underlying principle is straightforward. When biomass such as crop residues, forestry by-products, or organic wastes decomposes naturally, much of its carbon is released back into the atmosphere as carbon dioxide or methane. Pyrolysis converts this biomass into a more stable form of carbon.
Once applied to soil, biochar decomposes very slowly, allowing a substantial fraction of carbon to remain stored for centuries or longer, depending on feedstock, production conditions, and soil environment. This durability makes biochar attractive for climate mitigation: it functions as a relatively persistent carbon sink while simultaneously delivering agronomic and ecological benefits.
Although often presented as a modern innovation, biochar has historical roots. The fertile “Terra Preta” soils of the Amazon, enriched with charcoal-like materials and organic residues, demonstrate how charred biomass can enhance soil fertility and retain carbon over long periods. While today’s contexts differ, this evidence supports ongoing scientific and practical interest in biochar as a scalable tool for sustainable land management.
Production methods strongly influence biochar’s properties and effectiveness. Pyrolysis is the most common technique, carried out in low-oxygen environments to prevent full combustion. Systems range from simple farm-scale units to industrial facilities processing large biomass volumes.
Gasification, which operates at higher temperatures, can produce energy-rich syngas alongside biochar, improving overall efficiency. Hydrothermal carbonisation uses heat and pressure in water-rich conditions, producing a char-like material with different characteristics that may suit particular soils or remediation needs. The best technology depends on local feedstocks, infrastructure, energy demands, costs, and intended applications.
Biochar’s benefits in soils stem from its physical structure and chemical characteristics. It typically has a highly porous matrix and large surface area, which can improve aeration and water-holding capacity. These features are especially valuable in sandy or degraded soils where moisture and nutrients are quickly lost.
Many biochars also exhibit useful cation exchange capacity, enabling them to retain positively charged nutrients and release them gradually. This reduces nutrient leaching and improves fertiliser efficiency. Some biochars are mildly alkaline, helping counter soil acidity and create better conditions for plant growth.
From a climate perspective, biochar contributes through several interconnected mechanisms. The most direct is carbon sequestration: carbon from biomass is stabilised and stored in soil rather than rapidly returned to the atmosphere. Healthier soils often support stronger plant growth, increasing future biomass production and potential carbon inputs.
Biochar can also influence soil microbial communities and nutrient cycling, which may affect nitrous oxide and methane emissions. However, these effects vary by soil type, climate, and management, making careful measurement and monitoring essential for credible climate claims.
Lifecycle considerations are critical. The net climate benefit of biochar depends not only on carbon permanence but also on emissions from biomass collection, transport, processing, and application. Inefficient or fossil-fuel-intensive production can erode benefits.
Conversely, modern systems that capture and utilise energy released during pyrolysis or gasification can improve overall carbon balances. When feedstocks are responsibly sourced and production is well designed, biochar can deliver strong net climate benefits compared with many less durable carbon offset approaches.
Scaling biochar offers opportunities but faces challenges. While it can be produced wherever sustainable biomass exists, economics, supply chains, and regional suitability limit deployment. Feedstock availability varies, and not all biomass is suitable.
High initial costs and uncertain benefits may deter farmers, and biochar’s effects depend on soil type, climate, and nutrient status. It is not a one-size-fits-all solution but a flexible tool requiring site-specific design.
In agriculture, biochar consistently improves soil structure, nutrient retention, and water management. By enhancing porosity and aggregation, it supports root growth and oxygen availability. Its nutrient-holding capacity reduces losses of nitrogen, phosphorus, and potassium, boosting fertiliser efficiency and lowering pollution, especially in highly weathered or sandy soils.
Biochar also provides habitat for beneficial microorganisms, aiding nutrient cycling and long-term soil organic matter.
Its water-retention properties help soils hold moisture longer, enabling crops to better withstand short dry periods and stabilising yields under variable rainfall. Combined with practices like mulching, crop rotation, and irrigation, biochar enhances resilience to drought.
Farmer adoption of biochar depends on clear, local evidence of benefits such as improved yield stability or reduced fertiliser needs. Demonstration plots, region-specific guidance, and extension support are crucial, while upfront costs and uncertainty remain barriers, especially for smallholders.
Adoption is more likely when biochar fits existing practices and farmers receive practical information on products, application rates, and expected outcomes.
Scaling biochar effectively requires supportive policies and strong governance. Production must be economically viable and environmentally sound, with consistent quality ensured through standards, quality assurance, and oversight. Governance must prevent misuse and align initiatives with broader sustainability goals.
Sustainable feedstock sourcing is crucial. Agricultural residues, forestry by-products, and urban green waste are ideal, avoiding competition with food production and preventing land conversion. Irresponsible sourcing, such as deforestation, undermines biochar’s climate and sustainability benefits. Properly managed, biochar supports circular economy models by turning waste into a valuable resource.
Economic incentives and market development can boost adoption. Subsidies, farmer trials, and credible carbon crediting reduce barriers, while strong networks connect producers, advisers, and farmers for effective application. With robust standards and supportive policies, biochar can scale from pilot projects to mainstream climate-smart agriculture and land restoration programmes.
Community engagement is essential for successful biochar projects. Because these initiatives affect land use, labour, and resource flows, communities should be involved early in planning and decision-making. When local knowledge is respected and benefits are shared fairly, projects are more likely to last.
Training, transparent communication, and strong partnerships between researchers, extension services, and farmers help ensure realistic expectations and appropriate application.
Biochar is not a silver bullet, but it is a powerful tool linking durable carbon sequestration with soil restoration and agricultural co-benefits. Its porous structure, nutrient-holding capacity, and water-retention properties support farmers, while its stable carbon delivers long-term climate benefits.
When matched to suitable soils and crops and produced responsibly, biochar can contribute meaningfully to climate mitigation, healthier soils, and more resilient food systems.
The views expressed here are those of the writer and do not necessarily represent the views of Sarawak Tribune. The writer can be reached at khanwaseem@upm.edu.my.
