Apolygus lucorum is one of the most important piercing-sucking insect pests of tea plant. In this study, we assessed the impact of intercropping young tea plants with garden pea Pisum sativum on the populations of A. lucorum and natural enemies, tea plant growth and metabolites, and soil nutrient status of tea plantation. Intercropping with flowering P. sativum var. arvense reduced the population density of A. lucorum, particularly between June 1, 2020, and June 15, 2021, with a peak reduction of 90.87%. The percentage of A. lucorum-damaged tea leaves in the tea-pea intercropping was also reduced, with the maximum reduction of 8.96% observed on June 15, 2021, in the intercropping group compared to the control. The tea-P. arvense intercrop had a minor impact on the populations of natural enemies, such as coccinellids, parasitoids, and syrphids in the tea plantations. The tea-pea intercropping increased the contents of soluble sugar, tea polyphenols, caffeine, and anthocyanins, and decreased the contents of free amino acids and catechins of the tea plant leaves, and finally improved the quality of tea. Effective phosphorus and quick acting potassium decreased significantly in the plots intercropped. Our research indicated that tea-pea intercropping has the potential to manipulate the population of A. lucorum and tea leaf damage, and improve tea quality, while also enhancing soil fertility in tea plantations. The findings from this study offer important insights into the use of intercropping as a sustainable agricultural practice.

Intercropping in tea plantations offers multiple ecological and agronomic benefits, directly impacting tea yield and profitability. While most studies on intercropping focus on summer and autumn seasons, the ecological impacts of intercropping during spring remain underexplored. Building on initial findings that tea-rapeseed (Brassica napus L.) intercropping reduced pest damage in spring, this study explored its broader ecological effects on tea plantations and tea plant development. Results indicated that tea-rapeseed intercropping reduced young shoot damage byApolygus lucorum by 44.04 %, facilitated by enhanced soil-microbe interactions, modified spectral ecology, and activated defense pathways in tea plants during the profuse flowering period of rapeseed. Specifically, intercropping increased C and N availability in tea rhizosphere soil, boosting organic matter and nitrogen content in the shared ecological zone. This improvement was accompanied by a significant increase in the abundance of nitrogen- and phosphorus-cycling microbial taxa, such as Methylomirabilota, Armatimonadota, and Entotheonellaeota. Moreover, rapeseed intercropping altered canopy reflectance, increasing red-edge and near-infrared spectraand boosting NDVI by 5.97 %. GC-MS analysis revealed upregulated flavonoid biosynthesis and ABC transporters, leading to higher levels of antioxidants and defense compounds in tea shoots. Concurrently, predator populations (spiders, ladybirds, and hoverflies), increased by 5-7 times from rapeseed flowering to pod stages. These findings highlight the ecological and agronomic benefits of tea-rapeseed intercropping in spring, providing a foundation for sustainable tea plantation management and pest control strategies.