Abstract
<title>Abstract</title> <p> Sustainable management of perennial agroecosystems requires strategies that maintain crop productivity while enhancing soil health and ecosystem functions. However, the interactions among soil biological processes, crop performance, and quality formation remain insufficiently understood in tropical tea production systems. This study evaluated the effects of organic and conventional management on soil–plant interactions in Oolong tea ( <italic>Camellia sinensis</italic> L.) agroecosystems in the Central Highlands of Vietnam. A two-season field experiment using a randomized complete block design was conducted to assess crop productivity, soil properties, microbial biomass, phytochemical quality, and ecological pest regulation. Organic management resulted in a moderate reduction in fresh tea yield (− 9.2%) but improved soil ecosystem indicators, including soil organic carbon (+ 33.0%), total nitrogen (+ 33.3%), microbial biomass carbon (+ 45.3%), and soil moisture retention (+ 24.6%). These improvements were accompanied by increased polyphenol content (+ 18.1%), catechin concentration (+ 15.6%), and antioxidant activity (+ 15.2%). Correlation and multivariate analyses showed strong associations between soil biological indicators and tea quality traits, suggesting that improved belowground functioning contributes to enhanced ecosystem performance. These findings demonstrate that organic management can strengthen soil biological functions while maintaining productive and high-quality tea agroecosystems. The results provide insights into sustainable management strategies for perennial tropical cropping systems. </p>