**4. Indigenous microorganisms**

Indigenous microorganisms are naturally occurring microorganisms that have adapted to the environmental conditions where they are found thus being capable of accelerating decomposition of organic materials found in that environment [48]. They contain mainly Lactobacillus and sometimes Rhizobium with a few other species [49]. Effective microorganisms are composed of mixed cultures of beneficial and naturally occurring microorganisms which are applied to the soil in order to increase the soil microbial diversity and the growth of plants [50]. This concept was first discovered by Higa [51]. It is used as a means of improving crops' efficiency in utilizing organic matter. There are three main families of over 80 different species contained in effective microorganisms [52]. In agriculture, microorganisms are of great importance because they promote decomposition, cycling and circulation of plant nutrients and reduce the need for chemical fertilizers [53]. From the study of Desire et al. [53] the use of biofertilizers obtained from indigenous and effective microorganisms significantly improved and maintained the chemical, physical and biological properties of the soil, and thus increased the yield of potato in terms of number and weight of tubers when compared to untreated (control) soil.
