Yield Response to Different Planting Geometries in Maize–Soybean Relay Strip Intercropping Systems

Planting geometries directly affect crop yields in intercropping systems. Two different field experiments were conducted in 2012–2013 to analyze how different planting geometries in maize ( Zea mays L.) and soybean Glycine max (L.) Merr. relay strip intercropping systems at 2:2 maize‐to‐soybean affect yields. Maize plants were planted in narrow‐row planting patterns, whereas soybean was planted in wide rows. The effects of bandwidth, row spacing, plant spacing, and the distance between maize and soybean rows on crop yields were studied. Total intercrop yields were higher than those of sole crop maize and soybean, and the land equivalent ratios of the intercropping systems were above 1.3. The yield of the intercropped maize increased with bandwidth reduction at the same plant density, and similar results were found with increased maize narrow‐row spacing at the same bandwidth. Plant spacing had a dominant function when the bandwidth of the intercropped soybean was >200 cm. By contrast, the distance between maize and soybean rows had a dominant function when bandwidth was <200 cm. The optimum bandwidth and maize narrow‐row spacing in maize–soybean relay intercropping systems were 200 and 40 cm, respectively. These results suggest that the appropriate reduction in the spacing of the narrow maize rows and increase in the distance between maize and soybean rows could be used to achieve high yields in maize–soybean intercropping.