In a recent article published in the Egyptian Journal of Phycology, Essa and Razzaky explored the potential of using 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 derived from the marine macroalgae Ulva lactuca as a 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 for enhancing plant growth and physiological performance. The researchers produced biochar through slow 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 U. lactuca at 450°C under oxygen-limited conditions. The resulting biochar was characterized by low carbon and nitrogen content but elevated 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, phosphorus, and potassium levels, similar to poultry manure biochar.  

A greenhouse experiment was conducted to evaluate the effects of raw U. lactuca and its biochar on Pisum sativum (pea) seedling development. The researchers applied raw seaweed and biochar at different rates, both independently and in combination. Growth parameters, including root depth, shoot length, and fresh and dry 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, were assessed along with photosynthetic pigment concentrations.  

The results showed that all treatments significantly improved seedling growth and pigment content compared to the control group. The most pronounced effects were observed with the highest biochar application rate and its combination with raw seaweed. These findings suggest that U. lactuca biochar is a valuable organic soil amendment, particularly at higher application rates, with potential benefits for sustainable agriculture and crop productivity.  

Source: Essa, D. I., & Razzaky, E. O. (2025). Ulva lactuca Biochar: From Sea to Soil for Enhancing Sustainable Agriculture. Egyptian Journal of Phycology, 26, 48–60.