Earthworms With Low Dose n-MoS2 Improve Soybean Yield and Quality by Reconfiguring Rhizosphere Chemistry and Strengthening Nitrogen Fixation.

Abstract

Nano-enabled fertilizers can enhance biological nitrogen fixation (BNF) and yield in legumes; yet, their interactions with earthworms remain poorly understood. Herein, we performed a 120-day greenhouse experiment applying low-dose n-MoS₂ at 10 mg kg^-1 with earthworms to evaluate interactive effects on soybean yield and underlying mechanisms. Earthworms combined with n-MoS₂ treatment promoted Mo release and transport, with translocation and bioaccumulation increased by 44% and 26%, respectively. Furthermore, the rhizosphere soil shifted towards NO₃ ^- dominance while pH remained stable and consistent with sustained nitrification. Belowground, root system architecture expanded by 33%-82% and nodulation upregulated by 51%-61% relative to control. Similarly, leaf photosynthetic capacity was maximized by 23%-32% and gas exchange efficiency by 23%-27% under the n-MoS₂ with earthworm treatment. Additionally, NR, NiR, GS, GOGAT, and urease increased 30%-46% in shoots and 23%-43% in roots. Moreover, shoot and root N contents increased by 56%-68%, while nitrogenase activity and BNF increased by 40%-51%, respectively. Consequently, pods, seeds, and grain yield per plant increased by 90, 64% and 41%, respectively. Accordingly, seed protein and soluble sugars improved by 44% and 98%, respectively. Collectively, our findings show that earthworms amplify the efficacy of n-MoS₂, mobilizing Mo and strengthening BNF to deliver higher soybean yield and improved seed quality, supporting a practical, low-input strategy for sustainable production.