Emerging technologies in the development of biostimulants have opened the door for new opportunities to improve agricultural sustainability. The technological development has led to the promotion of microbial inoculant use as an alternative or supplement to traditional synthetic fertilizers and the reduction of agro-environmental associated problems such as leaching, pollution and greenhouse gas (GHG) emissions. These emerging products are being developed using beneficial fungi such as Arbuscular Mycorrhizal Fungi and free-living bacteria, especially Plant Growth-Promoting Rhizobacteria (PGPR) such as Bacillus species. Although, changes in anthropogenic activities are responsible for increasing atmospheric concentrations of GHGs, these bioinoculants as drivers of biochemical processes in soil, could cause a shift in ecosystem functions, reducing the production of CO2, CH4, and N2O. Various names have been given to the products e.g., biofertilizer, fertilizer helper, inoculants, biopesticide, etc. Regardless of which name, development of this biological approach has brought about a paradigm shift in nutrient use efficiency. However, the technology must be further improved because farmers’ acceptance and product use has not matched the growth of the subsector. This review examines the ongoing developments in the subsector, interrogates the identifiable impediments preventing broad acceptance, and discusses what is needed for improving the efficacy of these new approaches to better fit into an integrated nutrient management (INM) system.