Abstracts |
Crop mixtures, including agroforestry, hedgerow intercropping, mixed intercropping, strip (row) intercropping, and relay intercropping, are important in both traditional and modern agriculture. This article overviews the main systems of crop mixtures and summarizes the mechanisms behind overyielding, which happens in some crop mixtures. The mechanisms can be classified into interspecific above-ground and below-ground interactions between component crops. The former includes enhanced light interception (LI) and canopy heat capture, and the latter is related closely with interspecific facilitation and complementarity in acquisition and utilization of water, nitrogen, and insoluble nutrients (P, Fe, and Zn). In addition, crop mixtures can help control crop pests and diseases, which can also cause overyielding. |