biohiilen

Biohiilen, commonly called biochar, is a carbon-rich material produced by the pyrolysis of organic biomass under limited oxygen. It is used primarily as a soil amendment and as a means of carbon sequestration, with additional potential in waste management and water treatment.

Biohiilen is produced by heating biomass such as agricultural residues, wood waste, or manure at elevated temperatures in low-oxygen conditions. The process yields a stable carbon structure and a porous material. Pyrolysis temperature, feedstock, and residence time influence chemical properties, minerals, and surface area.

Biohiilen is highly porous with a large surface area, supporting soil microorganisms and helping retain water and nutrients. Depending on feedstock and processing, it can be acidic, neutral, or mildly alkaline and may contain minerals such as potassium, calcium, or phosphorus.

When added to soil, biohiilen can improve water holding capacity, reduce nutrient leaching, enhance soil structure, and support microbial activity. It also acts as a stable carbon sink, potentially sequestering carbon for decades to centuries. Some studies report yield gains, with results varying by context.

Effectiveness depends on soil type, climate, crop, and management. Use of low-quality or contaminated feedstocks can introduce pollutants. Biohiilen should be part of an integrated soil management strategy; it does not replace fertilizers. Life-cycle assessments help evaluate net climate benefits.

Biohiilen is the subject of ongoing research and policy development in sustainable agriculture and climate mitigation. Regional standards and guidelines exist in some areas, but practices and quality vary widely, requiring site-specific evaluation and monitoring.