The researchers found that the combined treatment reduced cumulative ammonia volatilization by 27.1 percent compared with conventional urea fertilization during a complete rice-wheat rotation. The result is particularly notable because the amended organic fertilizer was applied with a 30 percent reduction in mineral nitrogen input, yet crop productivity was largely maintained. The findings point toward a potential strategy for making fertilizer use more efficient without simply asking farmers to apply less and accept lower yields. Instead, the approach aims to control what happens to nitrogen after it enters the soil.

“Reducing fertilizer input is only useful if farmers can maintain crop production at the same time,” said corresponding author Haijun Sun. “Our results suggest that combining biochar with dicyandiamide in organic fertilizer can help balance these goals by retaining nitrogen, limiting ammonia losses, and supporting crop growth.” That balance is central to the global fertilizer challenge. Nitrogen is indispensable for plant proteins, chlorophyll, and growth, but when it is converted into gaseous ammonia and lost from farmland, farmers may need to spend more on replacement fertilizer while nearby communities and ecosystems absorb the pollution.

The experiment covered two complete rice and wheat rotations from 2022 to 2024 in greenhouse soil columns. The researchers compared conventional urea fertilization with three treatments that used lower amounts of mineral nitrogen: conventional organic fertilizer, organic fertilizer amended with biochar, and organic fertilizer containing both biochar and dicyandiamide. The soil-column design allowed the team to monitor nitrogen movement and ammonia emissions under controlled conditions over successive crop seasons. Unlike a short laboratory test, the two-year rotation captured repeated changes in soil chemistry, crop uptake, and fertilizer behavior across both flooded rice and relatively dry wheat production.

Among the treatments, the combination of biochar and dicyandiamide produced the most consistent result. Across the full rotation, it was the only organic fertilizer treatment that significantly reduced cumulative ammonia emissions compared with conventional urea. Biochar alone reduced cumulative ammonia volatilization by 5.9 percent compared with conventional organic fertilizer, while adding both biochar and dicyandiamide achieved a much larger 33.6 percent reduction relative to that treatment. These results suggest that the two amendments may work through complementary mechanisms rather than simply adding the same effect twice.

Biochar is a carbon-rich material produced by heating biomass under oxygen-limited conditions. Its porous structure can alter soil water retention, nutrient adsorption, and the chemical environment surrounding fertilizer particles. In this study, the researchers linked biochar application to better regulation of ammonium concentrations and pH in the soil and the floodwater covering rice. This matters because ammonia volatilization is strongly influenced by the balance between ammonium ions and dissolved ammonia. Higher pH shifts more ammonium toward gaseous ammonia, making it easier for nitrogen to escape. By moderating this chemical environment, biochar may help keep nitrogen in a less volatile form for longer.

Dicyandiamide, commonly known as DCD, is a nitrification inhibitor that slows the microbial conversion of ammonium into nitrite and nitrate. That process can be beneficial under some conditions because plants can absorb nitrate, but rapid nitrification can also increase the risk of nitrogen leaching and nitrous oxide production. By delaying the transformation, DCD may extend the period during which ammonium remains available for plant uptake or retention in the soil. The researchers observed altered nitrogen transformation patterns in the amended treatment, indicating that the inhibitor helped reshape the timing and pathways of nitrogen cycling rather than merely reducing one isolated emission.

The study also examined soil bacteria and found that biochar-containing fertilizers reduced the abundance of Nitrospirota, a bacterial group associated with nitrite oxidation, one of the key steps in nitrification. The shift suggests that the amendments may change the microbial niches involved in nitrogen conversion by modifying factors such as pH, moisture, carbon availability, and nutrient distribution. However, the researchers emphasize that their microbial analysis was based on taxonomic profiling. Detecting changes in the abundance of a bacterial group does not directly prove that a particular organism performed a specific biochemical function, so future work using functional genes, enzyme measurements, and isotope tracing will be needed to confirm the mechanisms.

The environmental gains did not appear to come at the expense of another major greenhouse gas. Cumulative nitrous oxide emissions showed no significant differences among the fertilizer treatments, an important finding because strategies that suppress ammonia can sometimes redirect nitrogen losses into other pathways. The combined treatment also maintained rice yields at levels comparable with conventional fertilization, while conventional organic fertilizer and biochar-only organic fertilizer reduced rice grain yields. The researchers estimated through Monte Carlo simulations that the combined treatment could generate potential benefits of approximately 36,600 Chinese yuan per hectare per year under the experimental conditions, reflecting fertilizer savings and reduced nitrogen-related environmental and health costs.

The result is promising, but it is not yet a universal prescription for farmers. The experiment was conducted in controlled soil columns rather than commercial fields, where rainfall, temperature swings, soil types, irrigation practices, fertilizer placement, and management decisions can vary dramatically. The economic estimate also depends on local fertilizer prices, crop yields, pollution costs, and the availability and quality of biochar and dicyandiamide. Field-scale trials will be essential to determine whether the ammonia reductions persist under real farming conditions and whether the treatment remains affordable and practical across different rice-wheat systems. Even with those limitations, the study offers a striking example of how combining carbon-based soil amendments with targeted nitrogen management could help turn fertilizer from a major source of pollution into a more efficient tool for feeding a growing population.

Subject of Research: Nitrogen fertilizer efficiency, ammonia volatilization, biochar, dicyandiamide, soil nitrogen cycling, and rice-wheat crop production

Article Title: Ammonia mitigation and economic gains from dicyandiamide and biochar-amended organic fertilizer: a 2-year rice-wheat rotation study

News Publication Date: 22-Jun-2026

Web References: https://doi.org/10.48130/aee-0026-0016; Agricultural Ecology and Environment

References: Huang W, Wang L, Gong X, Bian R, Lu X, et al. 2026. “Ammonia mitigation and economic gains from dicyandiamide and biochar-amended organic fertilizer: a 2-year rice-wheat rotation study.” Agricultural Ecology and Environment 2: e019. DOI: 10.48130/aee-0026-0016

Image Credits: Wang Huang, Lisha Wang, Xueliu Gong, Rongjun Bian, Xinyue Lu, Yuanqing Bu, Yunyi Liang, Haijun Sun, Yanfang Feng, Changlei Xia, Jiang Jiang, and Lihong Xue

Keywords: ammonia volatilization, biochar, dicyandiamide, organic fertilizer, nitrogen fertilizer, nitrogen cycling, rice-wheat rotation, soil microbiome, nitrification inhibition, sustainable agriculture, crop productivity, agricultural pollution

Liquid nano urea represents a novel class of nitrogen fertilizer that offers distinct advantages over conventional urea. The primary innovation in this formulation lies in its nanoscale size, which facilitates enhanced absorption by plant roots. This increased efficiency means that less nitrogen is required to achieve optimal growth, a substantial benefit considering nitrogen runoff’s negative effects on environmental quality. As nitrate can contaminate waterways, understanding and optimizing nitrogen use efficiency is essential for sustainable agricultural practices.

On the other hand, coated urea fertilizers have been designed to slowly release nitrogen over an extended period, which decreases the volatility of nitrogen gas through processes such as nitrification and denitrification. By coupling these advanced fertilizers with elevated CO2 levels, this study aims to identify intricate interactions that could potentially promote better nutrient uptake in crops. The findings are crucial in the context of improving crop resilience against climate stressors while optimizing input use to reduce environmental impact.

The study was conducted with various cropping systems, strategically chosen to mimic real-world agricultural conditions under future climate scenarios. Elevated CO2 and temperature settings were applied to examine their effects on crop yield performance and nitrogen use efficiency. Crop responses to these changes were measured by analyzing growth parameters such as plant height, chlorophyll content, and yield ratios. The results are poised to provide essential insights into the future of sustainable agriculture and food security.

One of the standout findings of the research was how liquid nano urea increased nutrient uptake in crops more effectively than conventional fertilizers. Enhanced nutrient absorption is vital for plant health and productivity. This study’s insights could translate into significant improvements in crop yield, vital for feeding an ever-growing global population while simultaneously addressing the environmental consequences of traditional farming practices.

Moreover, coated urea demonstrated remarkable efficiency in nutrient release, aligning with plant growth stages. By releasing nitrogen gradually, coated urea reduces the chances of nitrogen leaching into ecosystems, which can lead to eutrophication—a process that depletes oxygen in water bodies, adversely affecting aquatic life. This controlled release mechanism, combined with the dual stressors of elevated CO2 and temperature, indicates a strong potential for coated urea to enhance agronomic efficiency under climate change scenarios.

The implications of such findings are profound. As farmers grapple with the dual challenges of maintaining crop productivity while being stewards of the environment, these advanced fertilizer options will offer a pathway towards achieving both goals. The research suggests that adopting liquid nano urea and coated urea can improve nitrogen management strategies, aligning agricultural practices with sustainability objectives.

Furthermore, the study called attention to the likely future of crop management systems that integrate advanced fertilizers with precision farming technologies. By leveraging data-driven decision-making tools, farmers can optimize fertilizer application timing and quantities based on real-time environmental conditions, further enhancing agricultural productivity and minimizing waste. This approach aligns with the growing movement towards regenerative agriculture, which emphasizes sustainable soil health and ecosystem stewardship.

As countries around the world face strict regulations regarding greenhouse gas emissions, improving nitrogen use efficiency while reducing gaseous N losses is increasingly critical. Thus, the findings from this study could guide agricultural policies supporting the adoption of cutting-edge technologies that drive sustainable farming practices. Policymakers must recognize such studies’ importance to translate scientific insights into actionable frameworks that support farmers in implementing these advanced agricultural techniques.

The chemical mechanisms underlying the interaction between various nitrogen fertilizers and plant systems must also be further explored. Greater understanding in this area could facilitate the development of future fertilizers that not only meet current agricultural needs but also possess enhanced environmental benefits. As agronomists continue to innovate, studies like this provide essential blueprints for integrating science and agriculture to foster resilient farming systems.

This research lays the groundwork for crucial discussions on the future trajectories of fertilizer technologies in light of climate change. Given the urgent need for solutions that not only enhance agricultural productivity but also safeguard the environment, the implications of utilizing liquid nano urea and coated urea in farming systems could transcend national boundaries, influencing global agricultural practices and policies.

In conclusion, this groundbreaking study highlights the potential of advanced fertilizer technologies in the face of climate change. The enhanced agronomic efficiency demonstrated by liquid nano urea and coated urea offers promising avenues for mitigating environmental impact while meeting the food demands of the global population. As the agricultural community navigates these challenges, embracing innovation will be pivotal in shaping a sustainable future for farming worldwide.

Subject of Research: The effects of liquid nano urea and coated urea on gaseous nitrogen losses and agronomic efficiency under elevated CO2 and temperature interactions.

Article Title: Effect of liquid nano urea and coated urea on gaseous N losses and agronomic efficiency under elevated CO2 and temperature interaction.

Article References:

Apoorva, M.S., Bhatia, A., Chakrabarti, B. et al. Effect of liquid nano urea and coated urea on gaseous N losses and agronomic efficiency under elevated CO₂ and temperature interaction. Environ Sci Pollut Res (2025). https://doi.org/10.1007/s11356-025-36986-0

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s11356-025-36986-0

Keywords: liquid nano urea, coated urea, nitrogen loss, agronomic efficiency, climate change, sustainable agriculture.