Invasive aquatic weeds like water hyacinth and duckweed are major biological stressors that disrupt freshwater ecosystems and damage local economies. In a comprehensive review published in the journal Plant and Environment, researchers Muntaha Munir, Aisha Nazir, Lubna Anjum, Misbah Noor, Samreen Aslam, Muhammad Akhtar, Laiba Amjad, Maira Amir, Saba Nazir, Mudassir Sabri, Amina Khalid, and Rehan Jameel explored how these problematic plants can be transformed into a valuable biochar. By using 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, these aggressive weeds are turned into a stable, carbon-rich material. This transformation not only provides a sustainable way to manage invasive species but also creates a powerful tool for improving agricultural soils and mitigating climate change through carbon sequestration.

The researchers found that biochar derived from aquatic weeds possesses unique physical and chemical properties that differ from wood-based charcoals. Because aquatic plants naturally absorb high levels of minerals from their environment, the resulting biochar is exceptionally rich in nutrients like calcium, magnesium, and potassium. When added to soil, this material acts as a slow-release fertilizer that provides essential macronutrients such as nitrogen, phosphorus, and potassium directly to crops. This mineral-rich ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion.   Ash Ash is the residue that remains after the complete More fraction helps reduce the dependence on expensive chemical fertilizers, making farming more cost-effective and environmentally friendly by cutting down on nutrient runoff and groundwater pollution.

One of the most striking results of the study is the dramatic impact on plant root systems. Soils treated with aquatic weed biochar showed a significant increase in root length, surface area, and 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, with root growth in some cases increasing by more than 144 percent compared to untreated soil. This massive boost in root development allows plants to explore more soil for water and nutrients, which is vital for survival in nutrient-poor or degraded landscapes. Furthermore, the porous structure of the biochar creates tiny habitats for beneficial soil microbes. These microbes assist in nutrient cycling and help plants resist environmental stresses like drought and high salt levels, leading to more resilient and productive agricultural systems.

Beyond plant growth, the application of aquatic weed biochar offers major environmental and socioeconomic benefits. It serves as a long-term carbon sink, effectively locking carbon away in the soil for centuries and helping to slow global warming. By turning a nuisance into an asset, this approach supports a circular bioeconomy that can generate rural employment and promote small-scale enterprises. While the researchers note that more long-term field trials are needed to standardize production and application methods, the current findings highlight the immense potential of aquatic weed biochar as a scalable, low-cost solution for restoring ecosystems and ensuring food security.

Source: Munir, M., Nazir, A., Anjum, L., Noor, M., Aslam, S., Akhtar, M., Amjad, L., Amir, M., Nazir, S., Sabri, M., Khalid, A., & Jameel, R. (2025). Soil-plant interactions mediated by aquatic weed biochar. Plant and Environment, 6(2), 53-66.