Photosynthetically active radiation determining yields for an intercrop of maize with cabbage

•PAR and rows was a negative linear function for intercropped maize and a positive logarithmic function for intercropped cabbage.•Relationship between yields and rows of the intercrop was a logarithm function, negatively for the intercropped maize and positively for the intercropped cabbage, respectively.•A positive linear function between yield and PAR in the intercropping system was developed for both the intercropped maize and cabbage.

In order to explicate influential mechanism for yields of an intercrop of maize with cabbage, seven treatments for different intercropping rows of two crops were designed and conducted in the central Shanxi Province of China, and yield and PAR for each component crop of the intercropping treatments were measured. PAR of intercropped maize was higher than its monocropping while PAR of intercropped cabbage was lower than its monocropping. PAR highlighted a decline trend for intercropped maize and an increase trend for intercropped cabbage with increased rows of two crops in intercropping, respectively. Relationship between PAR and the number of intercropping rows of two crops was a negative linear function for intercropped maize and a positive logarithmic function for intercropped cabbage, respectively. Grain yield of intercropped maize declined and fresh yield of intercropped cabbage increased with intercropping rows of two crops, respectively. Relationship between yield and the number of intercropping rows of two crops was a logarithmic function, negative for intercropped maize and positive for intercropped cabbage, respectively. Generally, a positive linear function between yield and PAR in the intercropping system was developed for both intercropped maize and cabbage. M4‖C6 is recommended for an optimum combination of this intercropping system.