Promoting agricultural waste-driven denitrification and nitrogen sequestration with nano-enabled strategy

Area of Science:

• Environmental Science
• Soil Science
• Nanotechnology
• Biotechnology
• Microbiology

Background:

• Nanotechnology and biotechnology show potential for improving food security via nitrogen (N) sequestration and reduced nitrate leaching.
• The effectiveness and safety of these approaches require comprehensive mechanistic evaluation.

Purpose of the Study:

• To investigate the N retention mechanisms in N-contaminated soil using nano-iron oxide (nano-Fe3O4) and straw.
• To evaluate the impact of nano-Fe3O4 and straw amendment on nitrate leaching and soil N content.
• To explore the role of microbial communities and functional genes in the remediation process.

Main Methods:

• Development of a soil remediation strategy using nano-Fe3O4 and straw in N-contaminated soil.
• Application of metagenomics techniques to elucidate N retention mechanisms.
• Quantification of subsoil N content and nitrate concentration in leachate.

Main Results:

• Subsoil amended with straw and nano-Fe3O4 significantly increased subsoil N content by 53.2%.
• Nitrate concentration in leachate was reduced by 74.6% with straw and nano-Fe3O4 amendment.
• Enrichment of functional genes involved in N-cycling, nutrient uptake, and microbial responses was observed.

Conclusions:

• Nano-Fe3O4 combined with straw is a pioneering and effective strategy for soil remediation.
• This approach enhances soil N sequestration and mitigates nitrate leaching.
• The findings support the potential for cultivating safe vegetables in high N-input greenhouse agriculture.