Abstract:

The maize/soybean relay-cropping experiment was conducted using three plant types of maize(with erect, semi-erect and flat leaves), and the mono-cropping soybean as control. The results showed that different plant-types of maize led to a different micro-climate for soybean growth, which was a direct factor leading to the changes in morphological and photosynthetic characters of soybean leaves after four-leaf age stage. Poor light resulted in lower SLW, photosynthetic rate, chlorophyl a/b ratio and higher LAI. And the more the shading, the lower photosynthetic ability and yield were. After harvesting maize, the photosynthesis inhibition is by shading at early stage of soybean could be ameliorated, its photosynthetic capacity recovered gradually. The restoration capability of soybean that in relay-cropping with erect maize was better than in others, and similar to that in mono-cropping at late growing stage. From the section at early bloom, we found that under shading, the leaf thickness decreased, epidermis cell became larger, cuticle became thinner, the differentiation of palisade tissue and spongy tissue was unconspicuous, intercellular space was larger. In conclusion, the relay-cropping with erect maize can reduce the shading stress and increase yield in soybean.

Key words: Relay-cropping soybean, Maize plant-type, Photosynthetic characteristics, Anatomy structure, Yield