In a study published in Scientific Reports, Rania A.E. Abdelzaher and colleagues investigated how transforming date palm agricultural waste into biochar could offer a sustainable, cost-effective, and climate-friendly solution for growing Fuerte avocado seedlings, particularly in arid regions like Egypt. Traditional avocado farming is often resource-intensive, relying heavily on synthetic nitrogen fertilizers which are costly and significant contributors to greenhouse gas emissions, notably nitrous oxide, a gas with a warming potential far exceeding carbon dioxide . Furthermore, managing the immense quantities of date palm waste generated annually in Egypt presents its own environmental challenge. The researchers addressed these issues by assessing the effects of date palm biochar produced at two different temperatures and incorporated into the growing medium at four concentrations.

The findings over the two consecutive growing seasons were compelling, confirming the hypothesis that biochar produced at the lower temperature and applied at the highest rate provides the most significant benefits. In the second year, this treatment showed the greatest gains in plant height, trunk diameter, leaf number, leaf area, and fresh root 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 it resulted in peak values for leaf chlorophyll content,and carbohydrate content. Root development, crucial for nutrient and water uptake, also responded positively to higher biochar application rates treatment yielding substantially greater root weight and length than the other treatments. Interestingly, the positive effects of the biochar, particularly on root fresh weight, became even more significant in the second year, with an overall stronger influence observed in the later stage of cultivation. The researchers attribute the superior performance of the 300^oC biochar to the fact that lower 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 temperatures preserve more labile organic compounds, 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 increase the cation exchange capacity, all of which enhance nutrient retention and bioavailability, directly aiding plant growth.

Beyond promoting robust growth, the date palm biochar also demonstrated significant climate benefits. The control treatment, which used chemical fertilizers, consistently produced the highest CO₂emissions. The application of biochar at a 30%rate led to a marked reduction in CO₂ emissions, with the 700^oC biochar being slightly more effective at reducing CO₂ emissions in 2023. However, in terms of the more potentN₂ emissions, the 300°C treatment was the most effective, recording the lowest emissions in the second year. This is likely due to the biochar’s higher concentration of functional groups available for ion exchange, which enhances ammonium adsorption, reducing the substrate for nitrifying microbes and thus curtailing N₂ production.

From an economic perspective, the shift from conventional chemical fertilizers to date palm biochar presents a compelling case. The control treatment (T1) had a total production cost of 3.00$ per seedling, which included 1.00$ for chemical fertilizers. In contrast, the 30% biochar treatment entirely eliminated fertilizer costs and even reduced the seedling production management cost, resulting in the lowest total production cost of 1.50$ per seedling. This cost reduction makes the 300°C treatment the most economically favorable option for avocado cultivation.

Furthermore, a significant finding related to avocado micropropagation was the substantial reduction in the total phenolic content of the leaves in the biochar treatments, showing the lowest values. High phenolic content typically complicates avocado tissue culture by inducing browning, so this reduction may significantly improve propagation success rates. The combination of enhanced growth, greenhouse gas mitigation, lower production costs, and potential benefits for propagation underscores the value of using date palm biochar produced at 300°C and applied at a 30% concentration as a viable, sustainable, and cost-effective strategy for avocado cultivation.

Source:Abdelzaher, R. A. E., Chen, D., Mostafa, L. Y., Nassar, S. A., Ashmawy, E. M., Wu, H., & Fan, Q. (2025). Enhancing avocado growth and soil sustainability using date palm waste biochar as a climate smart solution for greenhouse gas mitigation. Scientific Reports, 15(40348).