Intercropping legumes in the tea agroecosystem modulates tea quality and suppresses insect pest populations

Tea is a crucial industrial beverage and cash crop that has been facing the dire effects of monoculture cropping (MCC), the accretion of pesticide residues and pest resurgence aggravated by climate change, and the disproportionate use of chemical inputs. Legumes are the most prominent cover crops that can modulate tea quality and attract beneficial arthropods, in tea agroecosystems. This study examined the synergistic impacts of leguminous cover cropping (LCC) with soybean (S) and cowpea (C) on tea quality attributes and the population dynamics of key tea pests.

The results vividly demonstrated that, compared to MCC, LCC-S;C significantly enhanced the foliar concentrations of key bioactive compounds such as caffeine and theanine. However, LCC-S;C significantly diminished the foliar concentrations of soluble nutrients, including soluble sugars, proteins, free fatty acids, essential amino acids, and bioactive compounds like total polyphenols, and monomer catechins. Notably, LCC-S;C enriched the foliar concentrations of catechin (epigallocatechin, EGC) and the essential amino acid isoleucine (Ile). Additionally, LCC-S; C significantly reduced the population abundances of three key tea pests (Empoasca onukii, Ricania speculum, and Trialeurodes vaporariorum), thereby aiding in natural pest control.

The findings highlight that LCC presents a viable alternative to MCC, improving tea quality, while simultaneously reducing the population abundances of key insect pests, and supporting the development of environmentally benign and economically sustainable cultivation practices in tea plantations. © 2026 Society of Chemical Industry.