Background

The use of microbes that improve plant phosphorus (P) use efficiency is an avenue to boost crop yields while alleviating environmental impacts. We tested three microbial inoculants (Rhizoglomus irregulare alone – designated AMF; Pseudomonas putida alone – designated PSB; and R. irregulare and P. putida in consortium – designated AMF+PSB), combined with chemical fertilizers, in an intensive maize agricultural system.

Results

As hypothesized: (i) despite the native soil microbial community and the application of P fertilizer, the microbial inoculants enhanced plant P uptake from the soil by 14–60%, and consequently improved P acquisition efficiency; (ii) PSB and AMF+PSB plants produced ±50% more biomass per unit of P taken up, and consequently enhanced plant internal P use efficiency (i.e. the biomass produced per unit of P); and (iii) the combined inoculation of AMF and PSB provided the best results in terms of productivity and P use efficiency. Further, the microbial inoculants altered P allocation within the plant, reducing grain P concentration.

Conclusion

By testing the microbial inoculants under field conditions, our study clearly shows that the microbial consortium (AMF+PSB) increased maize productivity, and at the same time improved P use efficiency. Further, the use of these microbial inoculants was shown to be compatible with conventional agricultural management practices.

中文翻译：

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微生物群落在田间条件下提高玉米生产力并降低谷物磷浓度

 背景

利用微生物提高植物磷（P）利用效率是提高作物产量同时减轻环境影响的一种途径。我们在集约化玉米农业系统中测试了三种微生物接种剂（单独的不规则根球菌- 指定为 AMF；单独的恶臭假单胞菌- 指定为 PSB；以及不规则根球菌和恶臭假单胞菌联合体 - 指定为 AMF+PSB）与化肥相结合。

 结果

假设：(i) 尽管存在原生土壤微生物群落和施用磷肥，微生物接种剂仍将植物从土壤中的磷吸收量提高了 14-60%，从而提高了磷的吸收效率； (ii) PSB和AMF+PSB植物每吸收单位磷产生的生物量增加了±50%，从而提高了植物内部磷利用效率（即每单位磷产生的生物量）； (iii) AMF 和 PSB 联合接种在生产力和磷利用效率方面提供了最佳结果。此外，微生物接种剂改变了植物内的磷分配，降低了籽粒磷浓度。

 结论

通过在田间条件下测试微生物接种剂，我们的研究清楚地表明微生物群落（AMF+PSB）提高了玉米生产力，同时提高了磷的利用效率。此外，这些微生物接种剂的使用被证明与传统的农业管理实践兼容。