Fig 2- uploaded by Richard Brackin
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The soil food web with various indicators of soil health overlaid (black boxes). 

The soil food web with various indicators of soil health overlaid (black boxes). 

Source publication
Conference Paper
Full-text available
SOIL BIOLOGICAL HEALTH is a topic of great interest to sugarcane growers, although there is confusion as to what constitutes soil health. Many growers and consultants are unaware that beneficial organisms, rather than pathogens and pests, dominate the biological community in a healthy soil. Considering the vast diversity of soil organisms and their...

Contexts in source publication

Context 1
... of the organisms described above and others (e.g. beetles, protozoa) that have not been outlined here, interact to form a soil food web (Figure 2). While soil structure, soil water content, pH and soil temperature play roles in the structure of the food web, the primary driver of activity within the soil food web is organic matter, in which carbon is an energy source for the remainder of the food web (Stirling, 2014). ...
Context 2
... non-experts, the nuances of these assays are often lost and they are often interchangeably considered as measures of 'biology'. However, if the tests are grouped and overlaid on the soil food web (Figure 2) then the relevance of the various tests becomes clearer. For example, a nematode community analysis, where omnivorous and predatory nematodes are dominant to plant parasitic nematodes, indicates a healthy soil food web. ...


... Despite this challenge, biological associations continually demonstrate many important soil functions. Six key roles of soil microbes are: decomposition of organic matter (crop residue), mineralization of and recycling of nutrients, fixation of nitrogen, detoxification of pollutants, maintenance of soil structure, biological suppression of plant pests, and reducing parasitism and damage to plants (Stirling, 2014;Brackin et al., 2017). These functions are also very closely linked with both the chemical and physical properties of soil as they are dependent upon and contribute to the fluxes and flows of indicators such as pH, nutrients, soil structure, and aggregate stability, to name a few. ...
Ameliorating biological attributes of agricultural soils is desirable, and one avenue is introducing beneficial microbes via commercial biostimulant products. Although gaining popularity with farmers, scientific evaluation of such products in field-grown crops is often lacking. We tested two microbial products, Soil-Life™ and Nutri-Life Platform®, in a commercial sugarcane crop by profiling bacterial and fungal communities in soil and roots using high throughput phylogenetic marker gene sequencing. The products, one predominantly consisting of Lactobacillus and the other of Trichoderma, were applied as a mixture as per manufacturers’ instructions. Additives included in the formulations were not listed, and plots that did not receive the product mixture were the controls. The compositions of bacterial communities of soil and sugarcane roots, sampled 2, 5 and 25 weeks after application, were unaffected by the products. Soil fungal communities were also unaffected, but sugarcane roots had a greater relative abundance of three unidentified taxa in genera Marasmius, Fusarium and Talaromyces in the treated plots. Sugarcane yield was similar across all treatments that included a 25% lower nitrogen fertiliser rate. Further research must examine if the altered root fungal community is a consistent feature of the tested products, and if it conveys benefits. We conclude that putative biostimulants can be evaluated by analysing the composition of microbial communities. DNA profiling should be complemented by cost-benefit analysis to build a public information base documenting the effects of microbial biostimulants. Such knowledge will assist manufacturers in product development and farmers in making judicious decisions on product selection, to ensure that the anticipated benefits of microbial biostimulants are realised for broad acre cropping.