**1. Introduction**

Some of the strategies that can be employed to intensify agricultural output include planting high-yielding varieties, the use of synthetic crop protection agricultural chemicals, and the application of synthetic mineral fertilizers. For example, about 50% of increased agricultural production has been heavily linked to the use of synthetic mineral fertilizers [1]. This approach is, however, increasingly becoming unsustainable as it causes soil degradation, and the cost of required inputs is often

beyond the financial reach of communal farmers. These communal farmers constitute more than 80% of food producers in developing nations [2].

Alternative systems that are more suitable to sub-tropical and tropical smallholder farmers are the target. EM are thus an alternative for crop growth enhancement. EM are cultured, naturally occurring specially selected microorganisms that are beneficial to soil health with the potential to significantly improve plant growth and soil quality [3]. These organisms are made up of selected species, including predominant populations of lactic acid bacteria, yeasts, a small number of photosynthetic bacteria, and actinomycetes, among others. These microorganisms need to be mutually compatible with one another to coexist in a liquid culture.

Prof Teruo Higa from the University of the Ryukyus, Okinawa, Japan, was the first individual to develop the concept of EM in 1971. The improvement of crop quality, growth, yield, soil quality, and health after the inoculation of plant ecosystem or the soil with EM has been widely reported [4]. The application of the microorganisms has been shown to increase sweet potato, peas, and onion yield by 23, 29, and 31%, respectively [3]. Local microbial isolates are being used to produce different brands of EM in over 40 countries around the world. Several South African countries are now producing and marketing EM products including EMROSA (Pty) Ltd., EMLife, and Efficient Microbes among others. Although several companies now market EM products, their use is not yet widespread, but over the years, some commercial farmers have adopted them with positive results. As such, there is an increase in EM use. However, there is a lack of rigorous research on the usefulness of EM in crop production in South Africa, and Africa in general.
