Effects of Soil Nutrients, Cultivation Duration, and Planting Methods on Polysaccharides, Saponins, and Flavonoids in Asparagus cochinchinensis (Lour.) Merr.

This study investigated how cultivation conditions affect bioactive compound synthesis in Asparagus cochinchinensis through a 3-year field experiment at two sites. Results showed that soil nutrient management significantly influenced metabolite accumulation, with mixed fertilizer treatment increasing polysaccharide content by 31.5% (reaching 5.84% dry weight) compared with controls. Different planting methods demonstrated varying impacts on plant establishment and compound synthesis, with raised bed systems achieving 92.8% establishment success and reducing pathogen populations by 34.2% compared with flat ground cultivation. Temporal analysis revealed that bioactive compound concentrations exhibited distinct seasonal patterns, with polysaccharides showing maximum accumulation in late autumn (5.84% ± 0.23%) and minimum levels during early summer (2.68% ± 0.12%). Principal component analysis indicated that environmental factors explained 68.4% of growth parameter variation and 57.2% of bioactive compound concentration variation. Strong correlations were observed between soil moisture content and root development (r = 0.815), whereas organic matter content showed significant positive correlations with both plant survival (r = 0.843) and metabolite synthesis. The study establishes optimal cultivation protocols combining nutrient management, planting method selection, and harvest timing to maximize both biomass and bioactive compound production.