[Ecophysiological effects of multiple cropping of winter wheat-spring corn-summer corn in Huanghuaihai Plain].

Compared to sequential cropping of winter wheat-summer corn and mono cropping of spring corn, the ecophysiological effects of multiple cropping of winter wheat-spring corn-summer corn in Huanghuaihai Plain were studied. The results showed that under the multi-cropping, the crops occupied higher spatial niches during the period of reproductive growth. Ecological factors such as light, temperature, and air were improved, and plane light acceptance was changed into multistory light acceptance, which made the relative intensity of illumination in crop communities increased. Moreover, soil temperature between rows and wind velocity in planting strips were also increased. All these changes were advantageous to increasing the intensity and velocity of grain filling. The chlorophyll content and photosynthetic rate in functional leaves of crops were higher, which was the main reason of yield increase under multiple cropping.