Cárdenas-Aguiar, E.; Gascó, G.; Lado, M.; Méndez, A.; Paz-Ferreiro, J.; Paz-González, A. Characterization of BiocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More from Beach-Cast Seaweed and Its Use for Amelioration of Acid Soils. Land 2024, 13, 881. https://doi.org/10.3390/land13060881

Biochar, a carbon-rich product obtained from the pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More of organic material, is being explored as a solution for soil amelioration. Recent research has focused on biochar derived from beach-cast seaweed, an abundant yet underutilized biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More. This study examined the properties of biochar produced from seaweed collected from Cesantes beach in Galicia, Spain, and its effects on acidic soils.

The seaweed, including species like Ulva rigida and Fucus spiralis, was pyrolyzed at 300°C and 600°C for different durations. The resulting biochars were analyzed for various physical and chemical properties. It was found that higher pyrolysis temperatures resulted in more stable carbon structures with lower volatile matterVolatile matter refers to the organic compounds that are released as gases during the pyrolysis process. These compounds can include methane, hydrogen, and carbon monoxide, which can be captured and used as fuel or further processed into other valuable products.   More and higher fixed carbon content. This stability is crucial for long-term soil improvement.

Biochars produced at 600°C had significantly lower water-extractable organic carbon, indicating higher resistance to decomposition and potential for long-term carbon sequestration. In contrast, biochars produced at 300°C had higher levels of soluble organic carbon, which could enhance soil fertility immediately but might decompose faster.

When applied to acidic soils, these biochars increased soil pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More and macronutrient availability, demonstrating their potential to mitigate soil acidity and enhance nutrient content. Higher pyrolysis temperatures resulted in biochars with more pronounced effects on soil pH and nutrient availability, particularly in very acidic soils.

This study underscores the dual benefits of using beach-cast seaweed for biochar production: it provides a sustainable method to manage this biomass while creating a valuable soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More that can improve soil health and support agricultural productivity. The findings suggest that beach-cast seaweed biochar could be a cost-effective and environmentally friendly solution for soil amelioration, contributing to sustainable agricultural practices.