Advances in Water and Nitrogen Management for Intercropping Systems: Crop Growth and Soil Environment

Intercropping is an eco-friendly, sustainable agricultural model that significantly improves yield stability, nutrient use efficiency, and soil health through spatiotemporal niche complementarity, increases biodiversity, and improves soil health. Water and nitrogen play crucial roles in limiting and regulating efficient resource utilization and ecological sustainability in intercropping systems. Synchronizing water and nitrogen inputs to match crop demands optimizes the spatiotemporal distribution of these resources, alleviates interspecific competition, and promotes mutualistic interactions, which significantly impacts crop growth, yield, and soil environment. This paper reviews the mechanisms of intercropping and water–nitrogen coupling regulation, aligning water and nitrogen supply with crop growth patterns, spatial configuration parameters, irrigation management techniques, and environmental climate change, and explores the response mechanisms of water–nitrogen coupling on crop growth, yield, and soil environmental adaptation. It can provide some references for researchers, extension agents, and policymakers. Research indicates that water–nitrogen coupling can enhance photosynthetic efficiency, promote root development, optimize nutrient uptake, and improve soil water dynamics, nitrogen cycling, and microbial community structures. Intercropping enhances the climate resilience of agricultural systems by leveraging species complementarity for resource utilization, strengthening ecosystem stability, and improving buffering capacity against climate change impacts such as extreme precipitation and temperature fluctuations. Future studies should further elucidate the differential effect of water–nitrogen coupling across regions and climatic conditions, focusing on multidimensional integrated administration strategies. Combining precision agriculture technologies and climate change predictions facilitates the development of more adaptive water–nitrogen coupling models to provide theoretical support and technical guarantees for sustainable agriculture.