Biochar and Glomalin Combined
Most conventional agricultural units which have started using biochar tend to plough or otherwise cultivate the soil in order to kill weeds and aerate the soil to encourage bacterial activity.
Rather than encouraging bacterial activity by cultivating and incorporating composted manure into the soil and rather than using the adsorptive properties of biochar to prevent nutrient leaching and nitrification, we use biochar in conjunction with a high carbon mulch, a minimal dig system and with permanent presence of plant roots. The aim is to use biochar to provide optimal conditions for Arbuscular Mycorrhizal activity in order to maximise glomalin production (as opposed to maximising bacterial activity in order to make nitrogen available to crops).
It is hoped that the increased AM activity will ensure not only that enough major (NPK) nutrients but that the right balance of all minerals and nutrients are made available to crops as a result of the crop:AM symbiosis.
Encouraging glomalin and using biochar ensure that enough nutrients will be stored in the soil to ensure that the aplication of fertilisers is no longer necessary.
Here at Swansea Biochar we aim to maximise soil carbon regeneration by using biochar in conjunction with the criteria needed for AMF to proliferate.
The intention is that the adsorptive properties of biochar as well as its massive internal surface area will further encourage AMF activity by providing suitable habitats.
Research on the interaction between biochar and AMF shows that the biochar can enhance AMF activity but that there are some conditions where adding biochar can inhibit it. It is important to understand the criteria needed in order for this relationship to be positive.
In order to ensure the liklehood of a positive relationala between biochar and AMF:
1, The biochar should be produced at temperatures of between 450 and 500 centigrade.
2, The biochar should be made of herbaceous rather than non herbaceous material (for example brush rather than nut kernals)
3, The biochar should be finely crushed before use.
The biochar can then be used in different ways in order to increase AMF activity:
1, It can be incorporated directly in soil in which the criteria needed for AMF proliferation are met (see ‘Glomalin‘ section for a description of these criteria). Incorporating it will necessetate some digging and so is not ideal, although it is hoped that once incorporated digging will not be required.
2, It can be composted with other material to be used as a mulch. If mulching with manure or compost the biochar will also have the effect of stabilising some of the soluble nitrates, reducing pollution and increasing availability to plants. My preferred mulch is ramial chipped wood (RCW) composted according to the principles of Jean Pain. Being high in carbon, composted RCW is more stable than high nitrogen products and it appears to support fungal activity better (rather than the bacterial activity encouraged by manure applications).
3, Biochar can also be used as an ingredient in Bokashi and other fermentation and EM (enhancing micro organism) soil ammendments.
We grow annual and perennial vegetables, fruit and herbs whilst ensuring that all of the following practices are used:
1, Heat for cooking and hot water is produced by either tlud stoves (outdoor cooking) or rocket hybrid stoves (indoor use) in order to produce a continuous flow of biochar whilst maximising energy capture.
2, The biochar is added to the soil in a mulch of composted wood chip with some horse manure and other waste biomass.
3, Working horses are used for various jobs. Biochar and wood chip are used on the stable floors.
4, Hot water and methane is produced from the composting process (as with the Jean Pain method) in order to avoid need for fossil fuels and to avoid inefficient wood combustion systems.
5, Digging and other soil disturbance are minimised in order to preserve fungal hyphae.
6, Permanent live plant roots are always present in both the annual and perennial vegetable plots. This ensures that the symbiosis between AM and plants can be supported. In the annual vegetable beds, annual winter hardy green manures are sown into the mulch prior to harvesting the vegetables.
The reasons for promoting AM rather than bacterial activity are:
1, Stabilising carbon in soil in the form of glomalin reverses climate change.
2, The presence of stable carbon in the soil protects soil from erosion by increasing its binding and exchange capacaties.
3, The production of soluble nitrate and other fertilisers requires large energy inputs, produced by burning fossil fuels. Peak oil, climate change and consequent food security issues dictate that we have to find alternative ways of growing food. Rather than feeding the plants with fertilisers, AM have the effect of bringing distant nutrients in soil to the plant.
4, By encouraging AM rather than using conventional growing practices and fertilisers, food has a greater nitritional value. This is because the AM bring more than just nitrogen, phospherous and potassium to the plant, they bring a wide range of minerals and nutrients as required by the plant.