Background and aimsPlants influence the soil they grow in, and this can alter the performance of other, later growing plants in the same soil. This is called plant-soil feedback and is usually tested with monospecific soils, i.e. soils that are conditioned by one plant species. Here, we test if plant-soil feedbacks of inocula consisting of mixtures of monospecific soils can be predicted from the effects of the component inocula.MethodsChrysanthemum plants were grown in sterile soil inoculated with eight monospecific conditioned soils and with mixtures consisting of all pairwise combinations. Plant biomass and leaf yellowness were measured and the additivity was calculated.ResultsOn average, plant biomass in the mixed inocula was slightly but significantly (6%) lower than predicted. In contrast, when growing in mixed inocula, plants showed 38% less disease symptoms than predicted. Moreover, the larger the difference between the effects of the two monospecific soils on plant growth, the higher the observed effect in the mixture exceeded the predicted effects.ConclusionsWe show that mixed monospecific soils interact antagonistically in terms of plant growth, but synergistically for disease symptoms. Our study further advances our understanding of plant-soil feedbacks, and suggests that mixing soils can be a powerful tool to steer soil microbiomes to improve plant-soil feedback effects.

中文翻译：

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混合单一特异性土壤对植物-土壤反馈的协同和拮抗作用

背景和目的植物会影响它们生长的土壤，而这会改变同一土壤中其他后来生长的植物的性能。这被称为植物-土壤反馈，通常用单种土壤进行测试，即由一种植物物种调节的土壤。在这里，我们测试是否可以从成分接种物的影响预测由单一特异性土壤混合物组成的接种物的植物-土壤反馈。方法菊花植物在接种了八种单一特异性条件土壤和由所有成对组合组成的混合物的无菌土壤中生长。测量植物生物量和叶片黄度并计算相加性。结果平均而言，混合接种物中的植物生物量略低于预测值（6%）。相反，在混合接种中生长时，植物表现出的疾病症状比预期的少 38%。此外，两种单特异性土壤对植物生长的影响之间的差异越大，混合物中观察到的效果超过预测的效果就越高。结论我们表明，混合的单特异性土壤在植物生长方面具有拮抗作用，但对疾病症状具有协同作用. 我们的研究进一步加深了我们对植物-土壤反馈的理解，并表明混合土壤可以成为引导土壤微生物群落以改善植物-土壤反馈效应的有力工具。结论我们表明，混合单一特异性土壤在植物生长方面具有拮抗作用，但在疾病症状方面具有协同作用。我们的研究进一步加深了我们对植物-土壤反馈的理解，并表明混合土壤可以成为引导土壤微生物群落以改善植物-土壤反馈效应的有力工具。结论我们表明，混合单一特异性土壤在植物生长方面具有拮抗作用，但在疾病症状方面具有协同作用。我们的研究进一步加深了我们对植物-土壤反馈的理解，并表明混合土壤可以成为引导土壤微生物群落以改善植物-土壤反馈效应的有力工具。