Johnson-Su compost bioreactor modded and simplified (experimental) with:
-1- A hexagonal vertical star picket formation (driven into the ground) can be made, 6 short Rio rod guides driven into the ground supporting 6 vertical 150mm PVC pipes. Hessian cloth wrapped around the star pickets. Unmilled biochar bottom aquifer added. BMC, manure and biomass filling around the pipes. Pipes removed and the pipe void then filled with unmilled biochar for vertical biochar cores which act as irrigation points for the bioreactor.
Lots of aeration and watering is needed. For eg. 50% BMC, poultry manure, additional biomass and Enhanced Rock Weathering (ERW) dust could be co-composted. The ratio of ingredients will depend on the microbe, nutrient and mineral profiles of the biochar, manure, loam/soil and plants you want to grow. Normally, it's a ratio of Carbon/Nitrogen @30:1. Keep in mind that most of the Carbon is locked into the C matrix in the BMC hence a high BMC percentage is possible with additional C in the form of biomass is still needed. The ratio should be optimised with experimental compost trials which I intend to do.
When the composting is complete (after a variable time period) the hessian cloth, star pickets and Rio rods are removed for reuse in additional bioreactors.
Middens can be built around the compost piles after the composting has completed with clayey loam added eg.dug from swales. This material, 'BMC compost and loam' is the updated definition of 'Permafert', which was previously defined as a midden made from loam with biochar added, not necessarily BMC, and just about anything else organic added.
It makes logistical sense to build the bioreactors near the swales, pits, cut 200L drums or whatever your growing system happens to be.
-2- Could use a 'no dig' donut chicken wire structure based on wire mesh resting on 2 logs, kept in the shade, see below.
5.Same as above design but Permafert piles with central biochar cores in half of the Zai pits for '3 Sisters' planting
A design for '3 Sisters' (maize, beans and squash) growing. Square Zai pits (built last Spring) updated with central permafert mounds for drainage, central biochar cores linked to bottom biochar aquifers forming a T junction for water wicking and conservation, nutrient reclamation, microbe housing and Carbon removal. Flooding events will concentrate water via the berms in the 'moat' around the mound for outer mound irrigation and additional irrigation as needed via the central biochar cores which will irrigate the inner mound and to an extent fill the bottom aquifer.
6.Circular Zai pits with integrated central biochar cores and biochar bottom aquifers
My preferred Zai pit design, a little bit more earthworks than the square ones but better water distribution and wicking and easy to make consistent berms around the pit. Depending on the rainfall pattern (which will become more unpredictable with climate change), the berms could be C shaped if too much water is accumulating in the pits and/or the depth of the biochar aquifers could be modified for more (deeper) or less (shallower) water storage. These will be used for my next pit trial over the Summer and Autumn growing 3 different pumpkin varieties (hard-skinned gourds) in 1 metre diameter pits using unmilled biochar from agroforestry waste for the cores and bottom aquifers. I'm using a cross + of 2x1m lengths of thin bamboo screwed together in the centre as a guide for pit building.
7. The terrace permafert swale, biochar aquifer and biochar core system
8. Mediterranean swale with Permafert and integrated central biochar core and biochar bottom aquifer system
-A pump free and battery free system, which makes me happy as I have broken 4 water pumps.
Co-compost the BMC (50%) with manure eg.poultry, which is full of nutrients and minerals, and additional biomass if available eg.pea/lucerne straw + Enhanced rock weathering (ERW) rock dust eg.basalt (more minerals) in a Johnson-Su or modded Johnson-Su compost bioreactor with possible multiple units operating at once. Many other composting systems exist too.
The above swale system is untested. Anyone willing to experiment with it please contact me so we can share results after I build my experimental system too.
If the quality of the loam/other soil type is higher then less BMC is needed in the permafert and vice versa. In my salad greens trial, 25% BMC seems to be the right amount added to good quality clayey brown loam. The quality could take into account water retention, nutrient retention, mineral retention, soil structure and porosity, cation exchange capacity, soil biome and ultimately fertility (and more).
The biochar cores could be inoculated with additional microbes, either before or after building them. Since the biochar cores are the main irrigation points and would be regularly monitored with a moisture meter, they will always be moist to a variable degree. This could be perfect for microbe housing in the 3D biochar matrix. The system should self-regulate aka if the moisture content is too high in the core, the microbes will enter the permafert and if the permafert becomes too dry they will re-enter the biochar core. The only problem I see is if the pit or swale is flooded for an extended period of time, some microbes might die. The only way I can think of to check this would be taking permafert and biochar core samples before and after extended flooding events, to a lab and comparing the microbe colony numbers.
Samples of the permafert probably need to be taken from time to time after flooding events to check nutrient, mineral and microbe levels and determine if direct top-ups are needed in the swale.
Compost from the Johnson-Su bioreactor/donut chicken wire system could be added to the top of the permafert as a mulch in swale when needed. This will reduce water evaporation/increase water conservation and also enter the biochar matrix within biochar pieces in the permafert providing additional nutrients and minerals for soil biota and plant roots plus providing additional microbes. For interest, check out in google images 'Terra preta de Indio' to get some nice Terra preta 'soil profiles'. The modded idea is that over time the soil is replenished and maintained with additional layers of biochar/compost/permafert/Biochar Mineral Complex (BMC, Professor Stephen Joseph) inputs - or even with Terra preta if that's what you want to make.
BEAM extract is worth investigating too. Contact Dr Paul Taylor for more information.
If the clay is too deep to access, there's a possibility of making char-crete lined swales which, if made permeable, might retain water over similar time scales to clay. There are recipes on the internet for this.
If using bore water for irrigation, research can be done to determine the effectiveness of the biochar filtering out the Total Dissolved Solids (TDS) to an acceptable level for a given plant variety.
Planted out the '3 Sisters' in 8 of the pits, 4 pits with mystery multi-coloured maize from my friend and borlotti beans and squash and 4 pits with Blue Hopi Maize, Bush bean gourmet delight and squash. I found one pit wasn't draining properly so I didn't plant it out. The other 7 pits. 3 furrows per pit, of Ceylon Spinach, Malabar Red Spinach, Rainbow chard and rocket. I may have to build some thin bamboo trellises for the spinach.
I seeded 3 of my original Permafert swales with zucchini, the other 2 still has Sunchoke tubers.
I also implemented denser plantings this season using direct seeding rather than seedlings, assuming only some of the seeds will germinate and grow - which they did.
Here's an idea for a tree guild integrating a circular Zai pit for a tree eg. fruit, nut, biomass (prunings/primary use for biochar) etc. and a circular swale (using the 'Mediterranean swale..' concept) for growing annual/bi-annual/perennial herbs and vegetables, with keyhole access, and utilising the microclimate of the tree once established. Both the Zai pit and swale would have a milled bottom biochar aquifer. The swale is designed for flat land, using the vertical unmilled biochar cores (drain) connected to the bottom biochar aquifer (wicking). The brown strips are the preferably clay berms for water capture. The Zai pit would be a little scalloped so the water captured is concentrated at the centre, possibly with a well packed 50mm concentric buffer of unmilled biochar around the base of the trunk down to the top of the rhizophere, where the water will drain towards the root system where it is needed the most (experimental). This design/blueprint could be replicated to build a 'Food Forest' of tree guilds. Note that food forests are modelled on natural forests and have different layers/heights of species eg.7. There's no reason why the outer swale couldn't be used to emulate the understory of a forest using this principle.
Here's a conceptual diagram of 'Tree guild alleys', using the previous 'Tree Guild' design as a blueprint which could be built into a 'Food Forest'. A small tractor could be driven between the keyhole alleys for harvest collection and maintenance eg.prunings for biomass feedstock, dried next to a Kon-Tiki 'Essential' biochar kiln for easy access for biochar production. An IBC water container could be placed next to the KTE also for easy access, used to quench a burn in the KTE, with alley access and could be filled when needed.
In this integrated regenerative agroforestry growing system, there would be many microclimates to grow many different plants. I should also mention too that as with the original 'Tree Guild' design, the above design is for flat land.
Initially, there would need to be a source of biochar to establish the tree guilds which could be sourced from biomass obtained cleaning up a property (with a couple of KTEs), a medium scale biochar business (say 4 KTEs) or possibly from a large scale biochar operation using a large biochar kiln processing biomass waste (and there are many biomass waste streams in Australia and around the world still untapped).
Once the trees are established, the system could be built out using agroforestry waste biomass for more biochar.
Any thoughts about how we can improve the systems please send me a message on the contact page.