The effect of intercropping on phosphorus availability in plant–soil systems: a meta-analysis

Background and aims

Intercropping is an effective practice for increasing crop diversity and achieving sustainable agricultural development, especially in areas with limited agricultural land. Although the nitrogen turnover and trade-off responses of plant–soil systems to intercropping have been extensively studied, quantitative information on the association between P and crop productivity is lacking. Therefore, in this study, we aimed to elucidate the effects of intercropping on plant P concentration, uptake, and use efficiency and soil P availability.

Methods

We conducted a quantitative meta-analysis using a database containing 453 comparisons from 56 peer-reviewed studies.

Results

Intercropping significantly increased the soil available P concentration and phosphatase activity by 14.68% and 11.74%, respectively, compared with monocropping. However, the effects of intercropping on other P characteristics and grain yield were not significant. Among the evaluated influencing factors, crop type (cereal or legume) had the greatest effect on soil P availability, followed by soil pH and P fertilizer input. Regression analysis revealed that plant P concentration and uptake were significantly and linearly correlated with soil available P concentration and phosphatase activity. Notably, in maize–legume intercropping systems, maize exhibited increased P concentration and uptake and increased grain yield, whereas legumes exhibited constrained growth.

Conclusion

Overall, we determined that intercropping improves soil P availability, depending on the ecological environment, nutrient management, and intercropping system. This study serves as a valuable reference for effective P fertilizer input in cereal–legume intercropping systems under different management practices.