At the end of my last posting I had concluded, perhaps too hastily, that the risk of unbalance outweighed benefit with regard to the question of the role of sugar additives as a valuable constituent in fruit tree health. The real question, at least for me, has centered on the presence of abscised fruit and leaf litter forming part of the duff below a tree.
While reading about the primordial fruit forests in Kazakhstan, I came across a description of a forest floor carpeted with decaying and fermenting apples. In a wild fruit tree forest ecosystem where pathogens are not artificially mitigated, there is a decaying strata of fermented fruit sugar present that would appear to form a crucial trophic tier in the localized web. The questions I am asking have moved beyond whether or not add sugar, but how bacteria and fungi interact with one another in the arboreal rhizome especially after events which may result in a bacterial population spike such as a ton of fermenting fruit falling to the ground.
To the point, I found an interesting research paper entitled,
"An Apple Fruit Fermentation (AFF) Treatment Improves the Composition of the Rhizosphere Microbial Community and Growth of Strawberry Seedlings" by a group researchers who I believe are based in Beijing, China.
The Apple Fruit Fermentation (AFF) broth refered to in the title was made in a manner identical to that employed in Korean Natural Farming for Fermented Fruit Juice (FFJ). This technique is freely available online.
I am gradually learning very basic rudiments of Korean Natural Farming (KNF) and am in the early stages of implementing some of the techniques into the agriculture we have begun to establish. KNF utilizes foliar sprays of various local (indigenous) inputs, most of which are fermentations. One of these is something called Fermented Fruit Juice, commonly referred to as FFJ. These inputs are employed during specific growth phases of the plants and FFJ is used, if I am not mistaken, during the transition from growing to fruiting and during actual fruit maturation.
Back to the study: The AFF broth was applied as a foliar spray to strawberries and as some kind of introduction to the rhizosphere.
With the Foliar sprays, there were improvements in fruit quality and disease resistance due to a mild acidity knocking out pathogens. Improved growth, improved photosynthesis, better stress resistance, things of this nature.
The AFF broth applied to the Rhizosphere was described as beneficient, but again, this was for strawberries not trees. And, as Dr. Ingham described, there is a spike in bacterial dominance. Obviously in trees you are going for a super fungal dominate rhizome with extremely high ratios of fungi to bacteria. There is a frequent mention of the AFF used in combination with Bacillus licheniformis. This is a bacterium adapted to alkaline conditions that is being investigated elsewhere for use as an agricultural feather decomposer via fermentation to convert proteins into a digestible form of livestock feed, a super alkaline detergent, and as a dental solution to penetrate through layers of plaque. Evidently the combination of this bacteria in conjunction with a fermented apple broth resulted in significantly more robust strawberries...
The segment of the paper regarding the rhizosphere is what I'm most curious about and the bacterial dominance described is confusing due to the addition of Bacillus lichenformis. As I read about this subject, I encounter a consistent reaction to the addition of sugars in the rhizome in the form of a bacterial spike.
In an established fungal dominate arboreal rhizome to which a natural and cyclical population surge of bacteria is introduced through abscised, fermenting fruit, what is the trophic process that is occurring? Is it something to do with the absorption of now bio available compounds decomposed by the bacteria? Are the bacteria food for protozoa and nematodes?
Here is Dr. Ingham on what protozoa do:
"Protozoa play an important role in mineralizing nutrients, making them available for use by plants and other soil organisms. Protozoa (and nematodes) have a lower concentration of nitrogen in their cells than the bacteria they eat. (The ratio of carbon to nitrogen for protozoa is 10:1 or much more and 3:1 to 10:1 for bacteria.) Bacteria eaten by protozoa contain too much nitrogen for the amount of carbon protozoa need. They release the excess nitrogen in the form of ammonium (NH4+). This usually occurs near the root system of a plant. Bacteria and other organisms rapidly take up most of the ammonium, but some is used by the plant. (See figure for explanation of mineralization and immobilzation.)
Another role that protozoa play is in regulating bacteria populations. When they graze on bacteria, protozoa stimulate growth of the bacterial population (and, in turn, decomposition rates and soil aggregation.) Exactly why this happens is under some debate, but grazing can be thought of like pruning a tree – a small amount enhances growth, too much reduces growth or will modify the mix of species in the bacterial community.
Protozoa are also an important food source for other soil organisms and help to suppress disease by competing with or feeding on pathogens."
Here is Dr. Inham on the role of nematodes:
"•Nutrient cycling. Like protozoa, nematodes are important in mineralizing, or releasing, nutrients in plant-available forms. When nematodes eat bacteria or fungi, ammonium (NH4+) is released because bacteria and fungi contain much more nitrogen than the nematodes require.
•Grazing. At low nematode densities, feeding by nematodes stimulates the growth rate of prey populations. That is, bacterial-feeders stimulate bacterial growth, plant-feeders stimulate plant growth, and so on. At higher densities, nematodes will reduce the population of their prey. This may decrease plant productivity, may negatively impact mycorrhizal fungi, and can reduce decomposition and immobilization rates by bacteria and fungi. Predatory nematodes may regulate populations of bacterial-and fungal-feeding nematodes, thus preventing over-grazing by those groups. Nematode grazing may control the balance between bacteria and fungi, and the species composition of the microbial community.
•Dispersal of microbes. Nematodes help distribute bacteria and fungi through the soil and along roots by carrying live and dormant microbes on their surfaces and in their digestive systems.
•Food source. Nematodes are food for higher level predators, including predatory nematodes, soil microarthropods, and soil insects. They are also parasitized by bacteria and fungi.
•Disease suppression and development. Some nematodes cause disease. Others consume disease-causing organisms, such as root-feeding nematodes, or prevent their access to roots. These may be potential biocontrol agents."
Interesting.
To conclude, how do the members of this forum approach fallen fruit at the base of their trees? I think it's an important part of tree health in a healthy trophic system. In a barren fungicide, herbicide, and insecticide treated orchard floor without duff or wood chips the fruit would obviously be the only food source for rapidly reproducing contagions and harmful organisms. But on a biologically thriving fungal dominate strata, would not the addition of fermenting fruit in some capacity be an essential component of tree and trophic web health? What do you think? Do you leave a little fruit on the ground or do you take it away? If you take it away, do you then prefer to incorporate it into a compost later?
Karn Piana
Zone 7 Semi-Arid Steppe
Northern New Mexico
Edited 4 time(s). Last edit at 06/16/2018 09:10AM by Karn Piana.