Living organic soil from start through recycling
That was an amazing summation of some complex stuff. Thanks!
Well something like that. There are probably many species of bacteria/archaea which can fix atmospheric nitrogen but one which is mostly popularized.
Let's drop the N and just say nutrients. It could be that more N as opposed to other nutrients are delivered through predation but there certainly are other macro & micronutrients made available this way. Bear in mind that this is one way of nutrient uptake and nature has several back-ups.
Consider that the soil is holding sequestered nutrients bound to organic matter (and clay particles) by a chemo/electrical charge which is described by CEC (cation exchange capacity). When some of those nutrients are released into the soil solution it is released via exudes or organic acids exuded by either roots or bacteria/archaea (I'll use bacteria). These acids (eg. carbonic, citric, malate, oxolate, etc) create hydrogen molecules which cause the release (exchange) of the desired nutrient into solution. In the case where the bacteria has consumed the nutrient and it is later, itself consumed by a protozoa then the protozoa uses only 30 to 40% of that energy and the remaining 60 to 70% is expelled as ionic form nutrient availble to the root.
It appears that this method of uptaking the desired nutrient is more 'economically' viable for the plant. Rather than expending its precious resources to mineralize (release) these nutrients the bacteria and protozoa pull it off for her. There is evidence that the plant can begin the whole process by exuding carbon to attract and feed the type of bacteria needed for the job. Upon being fed this carbon the bacteria multiply like crazy and then start feeding on the surrounding organic matter (as described) which then causes protozoa to multiply like crazy.... (It's like I get you stoned and give you a piece of chocolate, you get the munchies and pig out on bread or kraft dinner)
There are studies indicating that this is the predominant way that many plants (like annuals) uptake nutrients and I believe you are correct in stating primarily nitrogen.
In the case of ACT, you have been feeding the bacteria over the period of the brew and they have multiplied. The food comes from both the [vermi]compost you used and feedstock. If there are also flagellates and/or naked amoebae (protozoa) in the ACT then you will have nutrient cycling going on as described above and when applied to the soil you will be providing some nutrients into the soil solution immediately available to the roots.
Additionally, many of those microorganisms may go dormant or die, contributing to the soil storehouse or some may continue to floursh, depending on the needs of the soil. If there is hyphae in your ACT it may continue to grow, binding soil particles and creating aggregate, providing moisture and air retention, microbial pathways, microbial food and contribute to degradation of organic matter into a form accessible to other organisms.
That is my take. I apologize if I made errors or missed anything. This was written hurredly.
That was an amazing summation of some complex stuff. Thanks!
exc. VAT) £6.20 or 10g forPrice
