Gifted as they are with such regenerative potential, lactic acid bacteria and their colleagues can be a game changer altogether in farming practices, to say the least. This can be achieved through the inoculation of agrowaste with microorganism cultures to produce bokashi, a soil amendment which adds nutrients and improves soil texture, via anaerobic fermentation as described above. The basic stages of the process are:

  1. Organic matter is inoculated with the microorganism cultures. These will convert a fraction of the carbohydrates in the input to lactic acid by homolactic fermentation.
  2. Fermented anaerobically for a few weeks at ambient temperatures the organic matter is altered and preserved, in a process closely related to the making of some fermented foods and silage. The preserve is normally applied to soil when ready, or can be stored unexposed to atmospheric oxygen for later use.
  3. The preserve is embedded into soil. This exposes it to air, whereupon the lactic acid oxidises to pyruvate, a fundamental energy carrier in biological processes.
  4. The oxidized preserve is soon consumed by the indigenous soil life, forming the basic input for building and sustaining the soil microbial food chain. Within a matter of few weeks at ambient temperatures the preserve is practically embodied in the surroundings through intense earthworm activity, such that the amended soil acquires a texture associated with vermicompost.

Homolactic fermentation emits no greenhouse gases, its overall equation being C6H12O6 (carbohydrate) → 2 CH3CHOHCOOH (lactic acid). Insofar as it is carried out under anaerobic conditions there is no input O2 so as to bind carbon or hydrogen molecules to form greenhouse gases (CO2 and CH4), that would inevitably escape from the substrate into the atmosphere. Furthermore, keeping the carbon molecules intact within the soil prevents its inherent bioenergy from going to waste. As a result, virtually all input carbon, energy and nutrients enter the soil food web, having been neither emitted as greenhouse gases and heat nor leached out. In this case we are dealing with a mildly endothermic reaction, emitting no energy, while the fermentation medium remains at ambient temperature.

The main use of bokashi that is described above is to recover value from organic waste by converting it into a soil amendment very rich in nutrients and energy. In fact this is due to the activity of the microorganisms which operate as amplifiers of recycling, the end result of the operation being a battery of bioenergy. A positive side effect is to increase the organic carbon content of the amended soil. Some of this is a relatively long-term carbon sink – insofar as the soil ecosystem creates humus – and some is temporary for as long as the richer ecosystem is sustained by measures such as permanent planting, no-till cultivation and organic mulch. Another side effect of recycling organic waste to the soil food web is to divert it away from local waste management streams and their associated costs of collection and disposal. Adapting such farming habits, besides its obvious merrits in terms of farming efficiency, eventually plays a key role in enhansing the income of smallholder farmers.

These conditions are in marked contrast to oxidative decomposition, as in the case of compost, which emits the majority of its input carbon and energy in the form of greenhouse gases (carbon dioxide and methane, in proportions determined by the method of decomposition) and as heat, since aerobic decomposition is an exothermic reaction. Decomposition also loses the key plant nutrient nitrogen (in the form of the potent greenhouse gas nitrous oxide and in ammonia). Despite common belief – quite persistent in organic farming cycles – that composting is a potential problem solver in the quest for recycling agrowaste, it seems that this practice falls short of its targets. This is because trying to solve the problem of dealing responsibly with the issue of recycling our solid agrowaste, in fact we transform it to a gaseous state, and what a gas! Furthermore recycling by composting deprives its outputs from almost all of the initial bioenergy potential leaving too little for the soil and the plant life that it hosts.

Summing up this brief tour to the magnificent microcosmos, we would like to pinpoint the benefits one can draw from the selective use of microorganisms, especially the excellent ability of bacteria –mainly the lactic acid ones – to break down carbohydrates and organic matter in general and to inhibit pathogenic activity in the environments they come into contact with. It is useful to remember that the microcosmos abounds and generously offers to us its inexhaustible potential for natural growth, health and well-being of our crops, thus relieving us from the need to resort to chemical or other ways as a substitute for natural processes. In short, within the framework of our interests as organic farmers, lactic acid bacteria and their collaborators are excellent mediators between the enriched organic matter, which we supply to the orchard’s ecosystem through recycling of the whole range of agrowastes, and the plants that benefit from the products of this mediation in terms of nourishment and protection.