Linking stuff together, Permaculture design.
Foreword
There are people around who refuse to believe in human-driven climate change. Some debate the role of increasing atmospheric carbon dioxide levels as being problematic. If this is your case then you can still read this article because you may understand the importance of soil carbon for plants.
In case you don’t know, Permaculture is a holistic design and engineering approach. Our end game is to redesign and rebuild all of our current systems in such a way that they become resilient, durable, productive, and ethical. All of our systems, agricultural, economic, social, housing, water, energy, everything.
What makes Permaculture stand out is the importance we place on connecting stuff together, it’s the opposite of the piecemeal approaches we generally see.
So let’s have a look at an example.
The water problem.
The global outlook is that we’re up a dry creek in a barbed wire canoe. The climate has been getting warmer and this is reducing the amount of water stored in the world’s soils. It’s lakes and rivers too, and there is less snow.
This study shows how bad it is and the researchers have estimated that “during the period 2000 to 2002, soil moisture declined by approximately 1614 gigatonnes, much larger than Greenland’s ice loss of about 900 gigatonnes (2002–2006). From 2003 to 2016, SM depletion continued, with an additional 1009-gigatonne loss.” Gigatonnes is a lot but maybe not very evocative, so how about this. Global groundwater loss and over-extraction are causing the Earth’s pole to shift, eastwards, at around 4.36 cm a year.
An associated problem is the global increase in the number of extreme storms. These drop a lot of rain over a short period and the land below is unable to absorb it so it runs off. Less snow means less snow-melt and what fell as snow now falls as rain. Rain runs off, snow melt is slower and more can infiltrate.
Linking up the solutions.
The problems noted above are linked to global climate change which is tied to greenhouse gas emissions, CO2 being the one we talk most about. It’s interesting to note that carbon stocks in terrestrial ecosystems have increased dramatically (from 0.5 to 1.7 gigatonnes) over the last decade. Given that deforestation has increased one wonders where this carbon is being locked away. In fact, vegetation/trees only sequester around 6% of the total above. An overlooked massive carbon sink, and one that has yet to be quantified, is the anaerobic sediments beneath standing waters. Dams, lakes, ponds etc.
Today’s buzz-term is regenerative hydrology. It describes what Permaculture designers have been doing for decades now. Yeoman’s book, ‘Water for every farm’, was a major inspiration for the two founders of Permaculture. I installed my first swale in 1993. Integrated water infiltration and storage systems coupled with strategies to increase the water retention capacity of soils and reduce evaporation are key to what we do.
The Keyline approach increases rainwater infiltration, as do swales, increased infiltration means less runoff. More soil humidity (but not excessive) increases vegetation which sequesters more carbon. No-till systems mean less soil carbon loss which means that the soil carbon stock increases, which, in turn, increases their capacity to retain humidity. As Permaculture designers tend to favour no-till agro-forestry systems and no-till agro-sylvo-pastoralism, considerable quantities of carbon are sequestered by trees. The system can be designed so that when the trees are mature they can be harvested for timber. The wood is used for building and the carbon is locked away for the lifetime of the building. If the building is well designed if ever it is demolished the timber can be reused.
We install micro-dams and multi-functional lakes and ponds to store water. This research highlights a sometimes overlooked advantage of these water bodies, they are a massive carbon sink, one that has yet to be quantified. The carbon is sequestered into the anaerobic sediments beneath the standing waters.
Wetlands can also feature in Permaculture designs, they are multi-functional. They are excellent for biodiversity, they produce a wide variety of edible or useful plants and they lock away carbon in the sediment.
We tend to prioritise integrating all the different elements in a system. This means calculating quantities and connections. A well constructed swale should have an overflow point, the excess water overflows at a designed point. It can flow into a wetland area, or into a pond or lake. These have overflow points too and the excess can go into storage cisterns, down-flow lakes, ponds, an irrigation system or a wetland.
Another way of increasing infiltration and reducing, or slowing run-off is to plant hedges. Again, this is Permaculture, they will be multi-functional. This study shows that well-designed hedges can increase soil carbon by up to 40%. They are also great for biodiversity, they can be used to create paddocks for holistic grazing and they can produce fruit, nuts, and firewood. Put some N-fixing trees in, Alder (Alnus) for example and we increase the multi-functionality of the hedgerow. Alder aren’t leguminous (Rhizobia) they are in symbiosis with Frankia an actinomycete N-fixing bacteria. N-fixing shrubs are good too, you can pick one or two from the Genisteae family, Broom, Gorse … Laburnam are in this family too, and as small trees they can fit right in.
Landfill
The authors of study cited above point out that we stock away a lot of carbon in landfill sites. Disposing of garbage by burying it isn’t something that can continue, we have to redesign our systems to avoid this. The World Bank estimates that ‘Some 37 percent of waste is disposed of in some form of a landfill, 8 percent of which is disposed of in sanitary landfills with landfill gas collection systems. Open dumping accounts for about 31 percent of waste, 19 percent is recovered through recycling and composting, and 11 percent is incinerated for final disposal.’
The Bank also points out that ‘High-income countries generate relatively less food and green waste, at 32 percent of total waste, and generate more dry waste that could be recycled, including plastic, paper, cardboard, metal, and glass, which account for 51 percent of waste. Middle- and low-income countries generate 53 percent and 57 percent food and green waste, respectively.’
A permaculture axiom is that ‘any unused resource in a flow is pollution’, food waste is a good example of this. The landfilled food waste will ferment and produce methane so it is doubly polluting. A valuable resource is buried away instead of being recycled through composting or to produce biogas.
We design to avoid toxic inputs, plastic for example, and to create flows that mean everything is cycled again and again in the system. Food crops → food → food residue → compost/biogas → croplands → food crops → ad infinitum. Water is used, cleaned, cycled, or released to flow on. Efficient resource use and cycling means no pollution. This also means that we’ll have to stop relying on landfill as a carbon stock.
The wicked problem
Another interesting point is that increased per capita income means higher carbon emissions. More disposable income means more consumption which leads to more emissions. Good Permaculture design tends to increase people’s disposable income because it reduces spending needs.
Insulating the buildings is a good example of reducing spending by reducing waste.
Does this mean that a Permaculture design will increase carbon emissions? No, the whole system will reduce them, the increased disposable income is spent into the local economy and helps reduce emissions.
I hope this article demonstrates the power of good design and how the holistic approach at the heart of Permaculture is the way forward.