Influence of nutrient sources and beneficial soil microorganisms on the nutritional quality and bioactive compounds in vegetables
摘要
Vegetables are a vital component of the human diet, contributing substantially to nutritional security and overall health through their supply of vitamins, minerals, dietary fiber, and bioactive phytochemicals such as flavonoids and polyphenols. However, the continuous and excessive use of chemical fertilizers to maximize yields has disrupted soil structure, fertility, and microbial ecology, potentially impairing nutrient bioavailability, nutraceutical synthesis, and vegetable quality. The objective of this study was to evaluate the effects of different nutrient sources, with particular emphasis on organic amendments supplemented with plant growth-promoting microorganisms (PGPMs), on soil physicochemical and biological properties and their subsequent influence on vegetable nutritional, sensory, and nutraceutical quality. Results demonstrated that replacing chemical fertilizers with organic nutrient sources supplemented with a microbial consortium significantly enhanced soil health indicators, including soil organic carbon (+ 110%), phosphorus (+ 52%), zinc (+ 138%), iron (+ 86%), copper (+ 51%), and manganese (+ 44%). This improvement was accompanied by a substantial increase in beneficial soil microbial population, including fungi (87 × 10−3 cfu), bacteria (78 × 10−3 cfu), Trichoderma (92 × 10−3 cfu), Actinomycetes (70 × 10−3 cfu), and macrofauna such as earthworms (29.80 worms/m2), reflecting enhanced biological activity and improved rhizosphere functioning. Enhanced soil biological activity contributed to greater availability of essential macronutrients (N, P, and K), micronutrients (Fe, Zn, and Mn), and biologically active compounds, including organic acids, enzymes and phytohormone-like substances produced by beneficial microorganisms. Consequently, vegetables grown under integrated organic nutrient management with PGPMs inoculation exhibited superior quality attributes, with significant increases in mineral concentrations (+ 4.4% to + 31.9%), sensory attributes (+ 7.3% to + 27.4%), and nutraceutical content (+ 14.9% to + 55%), as well as higher antioxidant activity compared with crops cultivated using chemical fertilizers alone. Overall, the study highlights the potential of integrated organic-microbial nutrient management strategies to improve soil fertility and biological functioning while enhancing vegetable quality, thereby supporting sustainable agricultural practices and strengthening the nutritional foundation of human health.