Barley Growth and Phosphorus Uptake in Response to Inoculation with Arbuscular Mycorrhizal Fungi and Phosphorus Solubilizing Bacteria

Biostimulants and bioinoculants offer the potential to enhance nutrient use efficiency within agricultural cropping systems and thus reduce the amount of mineral fertilizers needed to support crop growth. Considerable uncertainty, however, exists about their efficacy under different management regimes. The present field-based study investigated the effects of phosphorus (P) solubilizing bacteria (PSB) and mycorrhizal (AMF) inoculants in the presence of a range of mineral-based P fertilizers, including triple superphosphate (TSP), struvite and rock phosphate (RP), on the growth, yield, and P uptake of barley (Hordeum vulgare L.). Two consecutive field experiments performed in a low P soil (Eutric Cambisol) revealed that the bioinoculants (PSB and AMF) promoted plant P uptake and grain yield. Moreover, in comparison to P fertilizers lacking bio-inoculants, the application of external P sources combined with bio-inoculants led to significant increases in leaf P concentration, total P uptake, plant dry matter, grain P concentration, and crop yield. Grain yield significantly correlated with P uptake by roots and above-ground parts (i.e. stems, leaves, and spikes) as well as grain P concentration in both seasons. It is concluded that bioinoculants can help improve sustainable P use ultimately leading to greater sustainability of cropping systems and resilience in soil P cycling.