Maize/peanut strip intercropping improves yield stability and potassium use efficiency

Intercropping systems enhance yield stability through resource complementarity, providing a sustainable agricultural approach. Potassium (K), a vital nutrient for plant growth, significantly influences crop yield and stability, although its regulatory mechanisms in intercropping remain underexplored. This study, based on field experiments from 2022 to 2024, assessed the impact of three K application rates (K0: 0 kg K₂O ha⁻¹, K1: 60 kg K₂O ha⁻¹, K2: 120 kg K₂O ha⁻¹) on yield and stability in maize/peanut monocrop (MS) and 8:8 strip intercropping (IS). Results indicated that IS significantly boosted maize yield while mitigating peanut yield loss, with a 23.82 % higher total system yield compared to MS. IS also demonstrated major yield stability under adverse climatic conditions (land equivalent ratio > 1). K application enhanced yield and stability, although the K contribution rate in IS was 52.16 % lower than in MS. Correlation and partial least squares structural equation modeling (PLS-SEM) analyses revealed a strong positive correlation between maize yield and overall system yield and stability. In IS, dominated by net diversity effects, K levels negatively regulated the compensation effect. Under K0, enhanced crop compensation significantly increased maize relative yield and maintained system stability. Under K1 and K2, IS yield was jointly promoted by diversity effects and K application, with no significant differences between K levels. In conclusion, maize is pivotal for IS yield and stability, while diversity effects enhance system adaptability to K levels and sustaining yield advantages.