Soil Nutrient Stoichiometry Improved Soil Carbon Storage and Crop Productivity Under Legume‐Based Strip Intercropping System

ABSTRACT Soil organic carbon (SOC) accrual is vital for mitigating climate change and building resilient agriculture ecosystems. Introducing agricultural practices based on crop diversification is crucial for efficient nutrient stoichiometric management and crop productivity. Therefore, this study aimed to evaluate the effects of different strip intercropping systems on SOC management, SOC and total nitrogen (TN) stocks, carbon management indices (CMI), as well as carbon, nitrogen and phosphorus (P) stoichiometry. Results indicated that SOC and total N were increased across all intercropping systems compared to monocropping. The land equivalent ratio (LER) ranged from 1.29 to 1.36, with a maximum value in the sesame–guar intercropping system, indicating yield advantage over monocropping. Total N and SOC stocks were enhanced by 96% and 66% during millet–mungbean and sesame–soybean intercropping, while maximum SOC mineralisation (32%) was observed in millet–mungbean intercropping. Sesame–mungbean increased the soil active carbon and CMI by 65%–163%, followed by millet–mungbean (50%–109%), sesame–soybean (64%–80%) and sesame–guar (63%–75%) in comparison with the sole cropping. Narrowed soil C:N and N:P ratios were found with strip intercropping, highlighting N and P mineralisation, which enhanced carbon accumulation, as compared to the mono‐cropping system. Increasing active carbon levels and nutrient availability such as nitrate and phosphate favour SOC storage due to reduced decomposition of stable carbon. However, soil C:N stoichiometry showed an exponentially declined nonlinear relationship with SOC stock, signifying that nitrogen availability played a critical role in soil carbon stabilisation. In contrast, the positive association of soil N:P ratio with SOC stock highlighted that balanced nitrogen is vital for SOC accumulation relative to phosphorus. It was concluded that legume strip intercropping inclusion in cereal crops enhances SOC stock, carbon management indices and optimises crop yield by enhancing soil multifunctionality while maintaining soil nutrient stoichiometry, particularly for low carbon agroecosystem.