The Effects of Wild (Native) Mycorrhizae Compared to Commercial Mycorrhizae Inoculants on Cool-season Grasses (Bromus inermis and Elymus canadensis)

Abstract

1. Premise of study

Due to the symbiotic relationship between mycorrhizae and host plants, many commercial forms of mycorrhizal fungi have been introduced to the market. Many commercial mycorrhizae inoculants include additives to assist in plant growth. For example, Plant Success Endo- and Ecto-Mycorrhizae consists of multiple arbuscular mycorrhiza (AM) and ectomycorrhiza (ECM) species, as well as, 3-1-2 N-P-K. Although these commercial inoculants are available for consumers, their effectiveness compared to native mycorrhizae has not been widely researched.

Methods

To test this, 48 seedlings (24 of each species:  Bromus inermis and Elymus canadensis) were transplanted into four treatment groups with six replicates per group: commercial inoculum present, living soil; commercial inoculum present, sterile soil; commercial inoculum absent, living soil; commercial inoculum absent, sterile soil. Each week, chlorophyll content was measured using a SPAD meter, blade height was measured, and both values recorded. At the end of the experiment, the aboveground and belowground biomasses were measured for each species.

Key results/Conclusions

There was a significant relationship between an increase in biomass of each plant species (B. inermis and E. canadensis) and soil treatment. Both plant species grew taller and with less variation in sterile soil conditions. However, each species struggled to survive in inoculated soils, regardless of the soil treatment (living or sterile). Overall, a significant relationship was not found between either species and the commercial mycorrhizal inoculant or wild (native) mycorrhizal fungi.