Mixed cropping of determinate and indeterminate soybean lines enhances productivity

• Published in: Field crops research 2023-02, Vol.291, p.108785, Article 108785
• Main Authors: Ye, Rongling, Tajima, Ryosuke, Sadaike, Ayumi, Saito, Daiki, Ogawa, Momoko, Kawamura, Issei, Ishimori, Shun, Nakajima, Takayuki, Uno, Toru, Kano, Kenichi, Ito, Toyoaki, Suyama, Yoshihisa, Kato, Shin, Kikuchi, Akio, Homma, Koki
• Format: Article
• Language: English
• Subjects: Determinate; Dry matter; Indeterminate; Land equivalent ratio; Leaf area; Mixed cropping; Ratio of yield to leaf area; Soybean
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/j.fcr.2022.108785

Similar to mixed cropping with different crop species, we hypothesized that mixed cropping of different lines of the same species, with complementary stem termination types, would benefit productivity. We investigated mixed cropping using breeding lines of soybean to test the feasibility of enhancing the yield. Field experiments were conducted with one near-isogenic line (NIL) combination and one residual heterozygous line (RHL) combination composed of determinate and indeterminate termination types of soybean plants for a total of five years. The trials found that mixed cropping had a positive effect on leaf area in terms of the land equivalent ratio (LER) in both combinations, while the effects on dry matter (DM) and yield changed depending on the genotypic background. The indeterminate type dominated the LER of DM and yield. The RHL combination had a 1.11 LER of yield on average but that of the NIL combination was 0.98. Mixed cropping enhanced the leaf area (LA) and the ratio of yield to LA of the indeterminate type and reduced those of the determinate type. The total yield increased when the enhancement of the indeterminate type was higher than the reduction of the determinate type in yield. The results of this study demonstrated that mixed cropping of the same crop with different termination types has the potential to enhance productivity, although depending on combinations. Further studies to reveal the mechanisms for finding optimal combinations are needed. •A new concept of mixed cropping of soybean lines has been demonstrated.•Mixing taller and shorter soybean lines increases leaf area per land area.•Higher productivity resulted from the enhanced growth of the taller soybean line.