Institute of Agricultural Sciences, ETH Zurich, Zurich, Switzerland.
Plant Production Systems, Agroscope, Nyon, Switzerland.
Elife. 2022 Sep 13;11:e77577. doi: 10.7554/eLife.77577.
By capitalising on positive biodiversityproductivity relationships, intercropping provides opportunities to improve agricultural sustainability. Intercropping is generally implemented using commercial seeds that were bred for maximal productivity in monocultures, thereby ignoring the ability of plants to adapt over generations to the surrounding neighbourhood, notably through increased complementarity, that is reduced competition or increased facilitation. This is why using monoculture-adapted seeds for intercropping might limit the benefits of crop diversity on yield. However, the adaptation potential of crops and the corresponding changes in complementarity have not been explored in annual crop systems. Here we show that plantplant interactions among annual crops shifted towards reduced competition and/or increased facilitation when the plants were growing in the same community type as their parents did in the previous two generations. Total yield did not respond to this common coexistence history, but in fertilized conditions, we observed increased overyielding in mixtures with a common coexistence history. Surprisingly, we observed character convergence between species sharing the same coexistence history for two generations, in monocultures but also in mixtures: the six crop species tested converged towards taller phenotypes with lower leaf dry matter content. This study provides the first empirical evidence for the potential of parental diversity affecting plantplant interactions, species complementarity and therefore potentially ecosystem functioning of the following generations in annual cropping systems. Although further studies are required to assess the contextdependence of these results, our findings may still have important implications for diversified agriculture as they illustrate the potential of targeted cultivars to increase complementarity of species in intercropping, which could be achieved through specific breeding for mixtures.
通过利用生物多样性与生产力之间的积极关系，间作提供了改善农业可持续性的机会。间作通常使用商业种子来实施，这些种子是为单作中的最大生产力而培育的，从而忽略了植物通过几代人适应周围环境的能力，特别是通过增加互补性，即减少竞争或增加促进作用。这就是为什么在间作中使用适应单作的种子可能会限制作物多样性对产量的益处。然而，作物的适应潜力以及相应的互补性变化在一年生作物系统中尚未得到探索。在这里，我们表明，当植物在与前两代父母相同的群落类型中生长时，一年生作物之间的植物-植物相互作用会朝着减少竞争和/或增加促进作用的方向转变。总产量对这种共同共存的历史没有反应，但在施肥条件下，我们观察到具有共同共存历史的混合物中出现了过度生长。令人惊讶的是，我们观察到在两代具有共同共存历史的物种之间，无论是在单作还是混合物中，都出现了特征趋同：在六种测试的作物中，向更高的表型和更低的叶片干物质含量趋同。本研究首次提供了有关亲本多样性影响植物-植物相互作用、物种互补性，从而可能影响下一代一年生作物系统中生态系统功能的实证证据。尽管需要进一步研究来评估这些结果的上下文依赖性，但我们的发现仍可能对多样化农业具有重要意义，因为它们说明了通过特定的混合品种培育来增加间作中物种互补性的潜力。
