Soybean has a high protein content in both its hay and seed. Studies have shown that the mixed cropping of corn and soybean improved forage yield and quality. The
objective
of this study was to select soybean germplasm suitable for mixed cropping with corn on the same row to produce better forage yield and quality. Eleven soybean lines selected from previous evaluations were used in this study. Soybeans were planted with corn on the same row at 10 cm intervals. The planting rate in hills was one corn plant and three soybean plants. The fertilization and time of forage harvest were based on the recommendations for forage corn production. The results showed that in corn–soybean mixed cropping, the forage yield increased by about 19%, the silage protein content increased by 1%–2%, the percentage of acid detergent fibers and neutral detergent fibers decreased, the total digestible nutrients increased, and the acetic acid content decreased. Therefore, the selected soybean lines were suitable for mixed cropping with corn to produce high quality forage and/or as breeding material for the development of forage soybean varieties. Based on this study, we suggest that the agronomic traits of soybean needed for mixed cropping with corn on the same row for forage are as follows: soybean should 1) have the ability to grow well under the corn canopy, 2) have lodging tolerance for ease of mechanical forage harvest, 3) develop to the full pod stage at the time of harvest for increased protein content, and 4) have no adverse effects on corn growth to maintain a high forage yield.