Trace Elements and Soil Microbiology
I have found that two of the biggest topics that even Grower’s customers are somewhat ignorant on are trace elements (both if they are in GMS and how much benefit they provide) and soil microbiological health. In the case of the latter, the past decade has seen soil microbe health come more to the forefront of mainstream agricultural conversations, but there is still a lot of mystery surrounding what effect our soil treatments (be that fertilizer or a soil amendment) have on them. In the case of the former, I believe that the proprietary nature of GMS' trace elements package and the fact that we don't recommend dumping individual packages into our mix has left some people wondering if we're pulling their leg, or at least if the package is as effective as we say it is. The experiment explained in this article can offer some insight into both of these questions.
Over the past year and a half, we have been experimenting with a kit called the microBIOMETER kit-that can measure soil microbe biomass and ratio of fungus-bacteria in real time. In this experiment, Matt Gooding mixed a clay-based soil uniformly and inserted pre-sprouted corn seeds into vials of the soil. The seeds were selected from the same cob and were selected for uniformity to remove variables from the experiment. Each of the 4 vials seen in the photograph was then watered with 500-1 dilutions of a 9-18-9 liquid fertilizer with no trace elements; GMS 10-20-10 with no trace elements; 11 TDS (total dissolved solids) water; and regular GMS respectively. After the corn had grown for a time, Matt took a soil sample from the top inch starting at the seed, and from one inch off the bottom of the vial, both of which he ran through the microBIOMETER. You can see the results for yourself in Table 4.
As you can see in Table 4, regular GMS (with trace elements) has the most positive effect on the biomass and fungus-bacteria numbers. For reference's sake, the soil was tested before any fertilizer or corn was put into it, and it had a biomass reading of 215 micrograms/milliliter. An increase from 215 to 333 is significant but is not unusual for what we have seen in other experiments. Please also note that GMS with no trace elements had a stronger positive effect on the biomass levels than the 9-18-9, though not as good as regular GMS. This suggests that, though trace elements are important for microbe health, purity of raw materials is also an important factor. All of the biomass levels dropped from the top to bottom samples, which is to be expected. Note that the sample with only water dropped the most, which would suggest that fertilizer choice and not just having a growing plant in the soil heavily impacts soil microbe health. Lastly, regular GMS consistently led to higher fungus percentages than the other treatments. Fungus is a very beneficial microbe to have in agricultural soils for soil nutrient mobilization and breaking down tough organic matter, amongst other things, so we should encourage its proliferation.
The focus of soil health has largely been on cover crops and tillage methods (i.e. no-till or minimum tillage). While these things certainly do have a role to play in soil health, many people are ignoring the effect that clean fertilizer and soil amendments have. What is the point of promoting deeper rooting, better soil structure, and constant sources of microbe food if it is being coupled with applications of toxic fertilizers?
This is an excerpt from the Late Fall Growers Solution (2022) written by Zach Smith, Product and Training Specialist.
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