Cereal-legume intercropping stabilizes yield and economic advantages under variable rainfall in semiarid rainfed environment

Cereal-legume intercropping is widely recognized for enhancing crop productivity in semiarid rainfed systems. However, the mechanisms underlying its yield advantages and stability under variable rainfall conditions remain unclear, limiting its adoption as a climate-resilient strategy. This study evaluated the stability of crop yield and economic benefits across inter-annual rainfall fluctuations (418 mm in 2019, 362 mm in 2020, and 253 mm in 2021) in a three-year field experiment. We assessed yield–economic performance of maize-soybean and wheat-soybean intercropping systems and their impacts on key soil functional parameters to elucidate the mechanisms underlying climate resilience. Both maize-soybean and wheat-soybean intercropping were observed to harvest 17–26 % higher yields (per plant) and 1.04–1.26 land equivalent ratios, therefore enhancing land-use efficiency. Economically, maize-based systems were the most profitable, while wheat-soybean intercropping turned to improve net returns by 1654 USD ha⁻¹. Climate-resilience analysis showed that intercropping reduced yield volatility by 10–61 % when precipitation declined (418–253 mm), highlighting its role in stabilizing agroecosystem productivity and economic benefits. Also, intercropping systems were found to significantly improve total nitrogen (13.7 %–20.6 %) and phosphorus (16.3 %–19.8 %). Mechanistically, the above indicators were resulted from improving soil microbial biomass (20.8 %–23.0 %), enhancing extracellular enzyme activities (9.3 %–15.8 % for C- and P-hydrolases) and promoting soil moisture retention (11.0 %–12.9 %). The data confirmed that intercropping can greatly enhance soil multifunctionality and thus contribute to yield and economic stability. Therefore, cereal-legume intercropping can act as a scalable strategy to enhance productivity, soil quality, and climate resilience in semiarid rainfed environment. The findings offer policymakers and smallholders a sustainable solution to balance land-use efficiency and climate adaptation.