Microscopic benefactors - more than nitrogen: Observations from field samples and trials showing increases in grain size, resistance to pathogens

Soil quality indicators have often been limited to the chemical and physical components of soil, due to difficulties surrounding the analysis of microbiological diversity, which include the high diversity found in soil, as well as challenges in lab-based culture mechanisms (Bünemann et al., 2018). Novel techniques to allow for isolation of soil microorganisms were developed by Brooks, (2017) to detect rarer and slower growing microorganisms in the soil. Novel metabolites were characterised by Gurusinghe et al., (2019) from organisms isolated using this method, showing that the maintenance of overall diversity of the soil provides great potential in the realms of drug discovery (Piddock, 2015) and in the isolation of compounds that may provide plant growth promoting effects (Çakmakçi et al., 2006; Kumar et al., 2016), bioremediation possibilities (Ruiu, 2013; Luo et al., 2014), or increasing the general nutrient profile of the soil. The work detailed in this article is an overview of some promising results in this sphere – the increase in grain size through bacterial inoculation during the growth of wheat plants at a test site in Lake Cargelligo, NSW, as well as the isolation of a bacterial species from a wheat crop in Wagga Wagga, NSW producing an exudate which experimentally acts as an oomycete filament forming inhibitor. The identification of bacterial diversity can also highlight and remediate other potential issues, such as the influence of an Alternaria species on the root development of a wheat crop noted (also in Lake Cargelligo, NSW). Whilst these are all promising results, they indicate a pathway for further research and the synthesis of microbiology and agronomy
to enhance crop performance.