Benefits of phosphorus fertilization in intercropping depend on cropping system: A meta-analysis

Abstract Aims Many agricultural soils suffer from phosphorus (P) deficiency. Intercropping could improve plant P uptake efficiency and yield compared to monocropping systems. How P fertilization affects yield and P uptake in intercropping remains unclear. Methods In this meta-analysis (including 907 observations from 39 studies) we evaluated how P fertilization influences yield, P and nitrogen (N) uptake in both intercropping and monocropping systems, and their Land Equivalent Ratios (LER) for different crops, soil types, management practices, and climatic conditions. Results Across all observations, P fertilization increased yields in both cropping systems. However, monocropping exhibited a greater increase in yield. Despite this, the LER increased under P fertilization, indicating that intercropping use land resources more efficiently, likely because certain crops respond more strongly to P fertilization compared to their companion crops. Most pronounced P fertilizer-induced increases in LER were observed in intercropping systems that had no cereals, while cereal yields in intercropping systems increased as much or less compared to monocropping. Positive relationships were observed between increased P and N uptake and yield with P fertilization in both systems. Notably, intercropping demonstrated enhanced efficiency in converting P uptake into yield gains compared to monocropping. Conclusions P fertilization improves yield, LER, and P uptake in non-cereal intercropping systems while cereal-based intercropping may be more favourable under low P availability conditions. Our findings further emphasize the role of fertilizer duration, soil factors (clay content and pH) and climate in increasing yields and LER with P fertilization, stressing the need for region-specific P management strategies.