Turning pesticide residues into plant nutrients: A new strategy for cleaner soils and healthier crops

Clothianidin, a widely used neonicotinoid pesticide, is notorious for its persistence in soils and accumulation in crops, posing risks to ecosystems and human health. Now, scientists have found a way not only to remove this pesticide from soil but also to transform it into a useful nutrient for plants.

A research team led by Dong He, Yujiao Wen, and colleagues at Hunan Agricultural University has developed a novel biochar-based catalyst that converts harmful pesticide residues into ammonium nitrogen—a form of fertilizer that supports crop growth. Their findings are published in Biochar (Springer Nature).

The researchers synthesized an iron–sulfur modified biochar (BC@Fe3S4) using a simple hydrothermal method. When combined with peroxymonosulfate (PMS), the material activated advanced oxidation processes (AOPs) that broke down clothianidin in contaminated soils. Remarkably, instead of leaving behind only degraded byproducts, the reaction released ammonium nitrogen, a nutrient essential for plant growth.

Greenhouse experiments with lettuce revealed striking benefits. In soils spiked with clothianidin, untreated plants showed pesticide residues and limited growth. But when the soils were treated with BC@Fe3S4 and PMS, no pesticide residues were detected in the lettuce, while plant dry weight nearly doubled compared to untreated controls. “We demonstrated that pesticide molecules can be decomposed into nutrients that crops can use directly,” said co-corresponding author Nan Zhou.

The study also analyzed the chemical pathways involved. Reactive oxygen species—especially hydroxyl radicals, singlet oxygen, and sulfate radicals—were found to drive both pesticide degradation and nutrient conversion. Toxicity simulations confirmed that the breakdown products were significantly less harmful than the original pesticide.

“This work provides a new perspective for soil remediation,” said Hongmei Liu, co-author of the study. “Instead of simply eliminating pesticides, we can recycle their nitrogen content back into the soil as fertilizer. It offers a win–win solution for food safety and sustainable agriculture.”

The findings are particularly relevant as neonicotinoid residues continue to be detected in vegetables worldwide, often exceeding food safety limits. Conventional remediation methods can remove these chemicals but do not typically recover nutrients. The biochar-based approach could offer farmers an affordable, scalable tool to improve soil health while reducing reliance on chemical fertilizers.

Looking ahead, the researchers note that long-term field trials will be essential to confirm the stability, safety, and practicality of this technology outside greenhouse conditions. They also envision extending the approach to other nitrogen-rich pesticides.

“Our results show it is feasible to simultaneously remove pesticide residues and replenish soil nutrients,” said co-corresponding author Zhonghua Zhou. “This could open a new path for sustainable agricultural practices.”

=== 

Journal Reference: He, D., Wen, Y., Wei, S. et al. Conversation of pesticide residues into ammonium nitrogen (NH₄⁺-N) through AOPs and its fertilization effect on lettuce growth. Biochar 7, 88 (2025). https://doi.org/10.1007/s42773-025-00465-z 

=== 

About Biochar

Biochar is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

Follow us on Facebook, X, and Bluesky.