Some friends of mine have just published their paper on Soil Bacterial Movement in European soils, I thought I would post the link to this paper here for your perusal.
Their work is along the same lines as some of my own, so of course I find it very inspiring and significant, I hope everyone here will too.
This is a great article. If their work is along the same lines of your work, then you do fun research! As a visual person who makes a lot of graphs for research papers, I really liked how Figure 4 broke down the contributions that pH, carbon, land use, and other factors made toward various bacterial measures. Between that graph and this sentence - "...soil properties, notably the pH and texture, appeared to be the main drivers of soil bacterial community composition and distribution at the European scale." - I came to realize how much pH, carbon, and texture affect the bacteria in the soil. I knew that these were important components of soil, but I hadn't considered how they affect the bacterial communities before. Thanks for sharing!
Even though plants can and will use certain exudates to regulate pH in the rhizosphere immediately surrounding their root systems, they lack the ability to extend the regulation of pH much further than 1cm.
That is why pH is so important, most bacteria and fungi have a narrow pH range that allows them to operate at peak performance levels.
Texture of soil plays a large part in allowing the pH to "normalize" so that the bacteria can remain at peak functional form for extended periods so that plant exudates have a maximum effect for the nutrients the exudate called for.
Carbon in the soil is not only useful for bacteria as the main anion/cation exchange medium but it also buffers other chemical reactions and stores some enzymes from the bacteria.
All this and then we add in the many functions of soil mycelium and the mycorrhizae and we end up with a soil internet or soil super highway that allows exudates to extend their influence from centimeters to meters and further distances from the roots sending out their calls for nutrients.
The distant bacteria pick up the exudate signals and then transport themselves to the near area of the plant(s) sending the exudate calls.
All the time these actions are going on, larger, single and multi cell organisms are moving along the same fungal network and feeding on the bacteria thus releasing any excess nutrients for any root system in that vicinity.
I am glad you like their work (they write really clear papers).