Gul, et al (2024) Co-application of Parthenium 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 and urea effectively mitigate cadmium toxicity during wheat growth. Ecotoxicology and Environmental Safety. https://doi.org/10.1016/j.ecoenv.2024.117092

Cadmium (Cd) contamination is a growing concern in agriculture, adversely affecting plant growth and food safety. With a focus on wheat—a globally important crop—researchers are exploring sustainable solutions to mitigate Cd toxicity in soil. One such approach combines biochar derived from Parthenium hysterophorus, an invasive weed, with urea to enhance soil fertility, improve plant growth, and reduce Cd accumulation in wheat.

Understanding Cadmium Toxicity

Cadmium is a heavy metal that, when absorbed by plants, can lead to stunted growth, reduced productivity, and health risks for humans through the food chain. Once in the soil, cadmium is not easily degraded, making its long-term presence a significant problem. Managing Cd in contaminated soils requires effective techniques that can reduce its bioavailability to crops, thus limiting its harmful effects.

Biochar and Urea: A Synergistic Approach

Biochar, a carbon-rich material produced by 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 matter, has gained attention for its ability to improve soil health and immobilize heavy metals like Cd. Biochar is known to enhance soil properties such as 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, water retention, and nutrient availability. When combined with urea, a nitrogen-rich fertilizer, these two amendments can work together to improve both plant growth and the soil’s ability to retain nutrients, reducing the uptake of Cd by plants.

In this study, biochar derived from Parthenium hysterophorus was combined with urea and applied to Cd-contaminated soil used to grow wheat. Seven treatment groups were established, including control (no amendments), Cd alone, biochar alone, urea alone, biochar with Cd, urea with Cd, and a combination of biochar and urea with Cd. The combined treatment of biochar and urea with Cd was found to have the most significant positive impact on wheat growth and Cd mitigation.

Key Findings

The combination of Parthenium biochar and urea significantly improved wheat growth in Cd-contaminated soils. The treatments enhanced shoot and root lengths, increased 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, and boosted chlorophyll content, which are indicators of healthier and more productive plants.

• Increased Growth: Wheat treated with biochar and urea showed a 65% increase in shoot length and a 70% increase in root length compared to plants grown under Cd stress without any treatment.
• Enhanced Cd Tolerance: The combined application of biochar and urea reduced Cd accumulation in wheat shoots by 51.3%, roots by 57.6%, and grains by 38.3%. This reduction was achieved by improving the soil’s physical and chemical properties, making Cd less available for plant uptake.
• Boosted Antioxidant Activity: The combination of biochar and urea increased the activity of key antioxidant enzymes—catalase, peroxidase, and superoxide dismutase—by over 50%, helping to mitigate oxidative stress caused by Cd exposure.
• Soil Health Improvements: The application of biochar and urea improved soil fertility by increasing the availability of essential nutrients like nitrogen, phosphorus, and potassium. Additionally, biochar helped immobilize Cd in the soil, reducing its bioavailability for future crops.

Environmental and Agricultural Benefits

This innovative approach to using invasive weeds like Parthenium hysterophorus as biochar feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More provides dual benefits. First, it helps control the spread of the invasive species by converting it into a valuable agricultural product. Second, it offers an eco-friendly solution to managing Cd toxicity in agricultural soils, contributing to both improved crop productivity and environmental sustainability.

The co-application of Parthenium biochar and urea offers a promising strategy to mitigate Cd toxicity in wheat cultivation. This approach not only enhances plant growth and soil health but also reduces the risk of Cd entering the food chain, promoting safer and more sustainable agricultural practices. As research progresses, this method could be applied to other crops and contaminated soils, providing a cost-effective and environmentally friendly solution for global agriculture.