Environmental Fate, Soil Ecological Responses and Fruit Quality Impacts of Emerging Contaminants (Antibiotics) in Orchard Ecosystems: A Review.

With the rapid development of intensive animal husbandry, the widespread use of livestock and poultry manure as organic fertilizers has become a major anthropogenic source of antibiotic contamination in agricultural soils. Antibiotics, classified as "emerging contaminants" owing to their persistence, biological activity, and potential ecotoxicity, undergo environmental fate processes such as adsorption-desorption, migration, transformation, and degradation upon entering orchard soils, with their behaviors regulated by multiple factors, including soil physicochemical properties, microbial communities, and climatic conditions. Antibiotics not only alter the structure and diversity of soil microbial communities, inhibit soil enzyme activities, and interfere with the cycling of carbon, nitrogen, and phosphorus nutrients but also induce the generation and dissemination of antibiotic resistance genes (ARGs) and affect the growth and reproduction of soil animals, triggering cascading effects on ecological processes. Moreover, antibiotics can be absorbed by fruit tree roots and transported to aboveground organs via the xylem or phloem. By interfering with photosynthesis, disrupting antioxidant systems, and affecting hormone balance, they inhibit the growth and development of fruit trees, thereby altering the appearance, nutritional, and flavor qualities of fruits. Furthermore, antibiotic residues and ARGs in fruits pose potential risks to food safety. This paper thoroughly analyzes the pollution levels, environmental interactions, and disposition of antibiotics in orchard soils, focusing on the mechanisms that influence their impact on soil microecology and biochemical processes. It also explores the absorption, transport, and accumulation patterns of antibiotics in fruit trees, as well as their effects on tree physiology, growth, fruit quality, and safety. Finally, the current research gaps and prospects are identified, aiming to provide a theoretical basis for ecological risk assessment, scientific prevention and control of antibiotic contamination in orchard ecosystems, and safeguarding of agricultural product safety.