Abstract: This paper studied the effects of different maize plant type and planting width on the early morphological characters and yield of relayplanted soybean under wheat/maize/soybean relayplanting. The results showed that different maize plant type led to different micro-climate in soybean planting strip, which was a direct factor affecting the changes in morphological characters and tissue structure of soybean. Large planting width and relay cropping with erect maize resulted in the short plant, thick main stem, large accumulation of dry matter, higher LAI and SLM, and high yield of soybean, while small planting width and relay cropping with flat maize led to the undergrowth of leaf and stem, overgrowth of plant, thin and lodgingsusceptible stem, and low yield of soybean. From the tissue sections of soybean leaf and stem at early blossoming stage under conditions of planted with different maize plant type and 1.17 m/0.83 m (soybean/maize) of planting width, it was found that under more shading, the leaf thickness decreased, epidermis cells became larger, cuticle became thinner, differentiation of palisade tissue and spongy tissue was inconspicuous, space between cells was large, epidermis and secondary xylem of stem all became thinner, parenchyma cells were loose, formulation of vessel delayed, and phloem fibers were less developed. It was concluded that relayplanting soybean with erect maize in a planting width of 1.17 m/0.83 m (soybean/maize) could be the best field combination in ensuring high yield and high efficiency all the year round.

Key words: water saving irrigation, light energy utilization, winter wheat, spike type, ¹³C assimilate distribution