Inoculum effect of arbuscular mycorrhizal fungi on soybeans grown in long-term bare-fallowed field with low phosphate availability

Abstract

Inoculation with arbuscular mycorrhizal fungi (AMF) can increase the growth of host plants, especially under condition of low phosphate (P) availability. Although this effect is shown relatively easily in simplified systems such as pot experiments, it is often hard to show in the field because of complicating factors such as competition with indigenous AMF. We conducted an AMF inoculation experiment with three Japanese soybean cultivars (Enrei, Misuzudaizu, and Akishirome) in an allophanic (Umbric Silandic) Andosol field under the long-term selective application of major nutrients (NPK and-P) and bare fallow. In the inoculation plots, introduced AMF were well colonized in soybean roots at flowering stage. In the-P plots, inoculation tended to increase the shoot dry weight of all the three soybean cultivars; this effect remained until harvest. Although a significant difference is not recognized, there was a tendency of residual effect on Enrei in the following year. In the NPK plots, inoculation did not significantly increase the shoot dry weight. We thought that in the-P plots, the long-term selective application of N and K and the long-term maintenance of bare fallow created the soil conditions of low P availability and poor native AMF. Thus, introduced AMF can benefit soybean growth and yield in the soil with low competitor AMF density and low phosphate availability.

Impact of Introduction of Arbuscular Mycorrhizal Fungi on the Root Microbial Community in Agricultural Fields

“…R-10 inoculum consists of 21 AM fungal OTUs that were employed as a tracking marker in the fields. However, these OTUs are also common in indigenous fungal communities (29, 48), and, thus, colonization of the inoculum fungus was only inferred based on relative increases in the abundance of R-10-type OTUs from those in mock-inoculated (control) plants. The cumulative abundance of R-10-type OTUs was significantly higher in inoculated plants than in mock plants in all fields at 1 MAT (Fig.…”

A friendly-environmental strategy: application of arbuscular mycorrhizal fungi to ornamental plants for plant growth and garden landscape

“…Notulae Botanicae Horti Cluj-Napoca Agrobotanici be expanded the absorptive area by 40 times and explore deeper water and nutrients (Giovannetti et al, 2001;Hayashi et al, 2018;Zhang et al, 2019a). Similarly, AMF regulate endogenous hormone levels to affect plant growth and flowering (Bi et al, 2019).…”

“…It was proved that extraradical mycelium of AMF contribute P requirements for up to 80% plants (Marschner and Dell, 1994) because the network of hyphae expands the volume of P absorption, but also secretes phosphatases to catalyze organic compounds into phosphate (Hayashi et al, 2018). The gene of P transporters is up-regulated by AMF to associate P uptake in many plants (Fellbaum et al, 2014).…”

The use of soil biostructures created by soil fauna ecosystem engineers fed with different organic matterials as inoculum source of arbuscular mycorrhiza fungi on cocoa seedling

“…The success of AMF spore inoculation under unsterilized growing media is determined by biotic factors through an inhibitory mechanism (Fukami, 2015), the spore community inhabiting the growth media has the potential to suppress the performance of pores carried by inoculum source material to infect roots (Werner & Kiers, 2015). Furthermore, the inhibitory effect's strength is supported by the nutrient availability in the growth media (Cely et al, 2016;Hayashi et al, 2018) The percentage of infected roots did not differ significantly between the control and biostructures treatments. However, the plant height and the number of leaves were higher in the control, compared to the biostructure treatments (Table 5 and 6), but the seedling's shoot dry weight was insignificant (Table 7).…”