Why you should test your soil for life – Part 4: Microbial Ratios
With general view on the basic organisms under our belt, let us turn to the importance of ratios and why these need to be just right in order to fully benefit from the increased efficiency of plant nutrient uptake and disease suppression brought about by microbial interactions.
If you have already indulged in our introduction to bacteria and fungi, you may already appreciate that planning the crop type is crucial, especially when reviewing the laboratory analysis and deciding on your course of action with nutrition. Some crops will naturally prefer more bacterial soil, others more fungal whilst some plants prefer an even balance. Using a tool, such as our Soil Surveillance System to keep track of soil test reports for growing areas and managing soil data is a great way to check in on your progress and adapt as you go.
In receiving your test data you will need to translate this to you particular crop type. These are generally categorised as follows, however it may be necessary through specific management regimes to target and alternative to the ‘norm’ and a good biological consultant may also advise a different level for a number of reasons:
AF/AB and TF/TB < 1
Crops suited to a more bacterial environment – In general this is not a preferred situation for a crop due to the high alkalinity that often accompanies this growing environment.
AF/AB and TF/TB > 1
Suited to crops that will prefer a more fungal environment – most woody plants and soft fruit including trees, shrubs and soft fruit like strawberries and blueberries.
AF/AB and TF/TB = 1
The optimum situation for crops in most cases, will be a balanced soil. This is the case for a wide variety of arable crops as well as salads, such as cucumbers and tomatoes.
In the case of inoculants, the balance between AB/TB is incredibly important when we consider the maturity and stability of what you are intending to apply. In compost this balance needs to be below 10% (indicating a mature compost). In liquid inoculates, higher ratios are better for foliage applications – the more active component being vital to actively protect the leaf surfaces from disease by out-competing with the harmful organisms. For soil application, of a liquid treatment, this balance may be less crucial as bacterial communities will become active in the soil environment. If you require a supply of quality compost for compost tea or liquid microbial extract and feed, drop me a line on my personal email. If you are developing a product or indeed producing your own inoculate it is therefore sensible to get this tested by a professional laboratory such as Soilbiolab as well as doing your own sense-check with a microscope during initial production.
Simon runs Mind, Body & Soil and is Cofounder of SoilBioLab. He specialises in services and solutions for soil fertility management. You can follow him on twitter @peat_free or email him at simon@mindbodysoil.co.uk