SCIENCE & SOCIETY INSIGHTS

Abstract

Wastewater reuse in agriculture has emerged as both a necessity and an opportunity in the face of global freshwater scarcity. While its use can improve water availability and reduce dependency on synthetic fertilizers, wastewater—especially when untreated—poses significant challenges across the soil–plant–atmosphere interface (SPAI). This review explores the complex interactions and consequences of wastewater irrigation, examining impacts on soil structure, microbial communities, nutrient balance, and heavy metal accumulation. It further analyzes physiological stress responses in crops, food safety concerns, and disruptions to evapotranspiration, greenhouse gas emissions, and plant–microbe signaling. The article reviews a range of remediation strategies, from low-cost treatment technologies (e.g., constructed wetlands, biochar filtration) to soil amendments, crop rotation, and precision irrigation. Emphasis is placed on integrated, context-specific approaches that combine technical, agronomic, and institutional solutions. Long-term sustainability of wastewater reuse depends on effective monitoring, risk mitigation, and adaptive policies that address emerging threats like microplastics and antibiotic resistance. The review concludes by identifying research priorities focused on system-level feedbacks within the SPAI and advocates for wastewater reuse strategies aligned with circular economy, food safety, and climate-smart agriculture goals.