Wednesday, August 01, 2018

Permaculture - Designing a Regenerative Future.

The following article has appeared (Pages 4-5) in Pulse, the flagship online magazine of the Linnean Society of London.

 The Linn Soc is the oldest continuously active society for the biological/environmental sciences in the world.

Permaculture is a portmanteau word (derived from permanent agriculture, or permanent culture) which describes a design system modelled on the functioning of natural ecosystems.  It is guided by three core ethics - Earth Care, People Care and Fair Shares. The first of these is fundamental, since without a thriving planet, ultimately we have nothing, and so the soil, water and air must be viewed as sacrosanct, and need to be protected and regenerated. The second ethic embraces an integrated philosophy of living, in which the large human population exerts a profound impact on this planet, and if we flourish as part of a regenerative, rather than a degenerative design, the Earth will become abundant with us. Estimates of the maximum maintainable population vary, however.

As labelled “Fair Shares”, the third ethic emphasises that each of us should take no more than what we need, but expressed alternatively as “Share the Surplus”, it means that any surpluses are returned to the system overall to support the other two ethics. The useful recycling of waste back into the system is in accord with the third ethic, since there is no “waste” in nature, and the notion of a "circular economy"  is based on this.
Two of the cornerstone permaculture design principles  are that “each element performs many functions” and “each important function is supported by many elements”. Accordingly, every element is chosen and placed within the design so to serve as many functions as possible (probably at least three). The design is “resilient” if critical functions are supported in a number of different ways, and continues to operate should any one element of the system fail.

Chikukwa Project.
When land has become badly degraded, especially in developing countries, it is often considered too expensive to recover using engineering/technological approaches and is accordingly “written off”. The Chikukwa project in Zimbabwe is an edifying example of how a thoroughly degraded landscape, with severely eroded soil, can be brought back to verdancy using low tech methods - and with very little money, but a good design - as can be seen from the “before and after” photographs (Figures 1 and 2). This is not a “quick-fix” strategy, and has taken over two decades to achieve; it has, however, created a sustainable landscape. The Chikukwa clan consists of 7000 members who live in 6 villages situated along a 15 km stretch of hills and valleys, and from Figure 2 it would be easy to think that they have simply continued to live a centuries-old life according to their traditions. In fact, the Chikukwa project began in 1991 when the water supply that had provided for around 50 households in the village of Chitekete suddenly dried up. Attempts to dig for water were thwarted by further rains which caused the stream to become silted up again. At this time, the area was being increasingly deforested, and the loss of vegetation from the formerly lush and abundant mountainsides exacerbated soil erosion which further compounded the water problem. Erosion had impacted badly on the fertility of the land, which was steadily becoming desert. The lack of normal groundwater recharge as a result of deforestation had caused the springs to dry up, and when new water sources were tapped, they became blocked by silt from erosion.

The drying up of the springs also had a spiritual dimension, since traditional beliefs demand that the water spirits who live in them should be cared for, by maintaining the health of the springs. In permaculture terminology, Chikukwa is well described as an edge, in terms of ecology, culture and language, and the edge effect has undoubtedly yielded a rich and active vibrancy in all respects. Every family has access to running water, taken from mountain springs; communal land in the valley is used to grow wheat and maize flower, providing bread and maize meal. Along the mountainsides are grown fruit trees which everyone can help themselves to. Nonetheless, this is a way of life remote in all respects from that in the developed nations, and the majority live in mud huts and provide for themselves and their families by subsistence farming.

RISC roof garden.
A fine example of what can be grown in unused urban space is the RISC Roof Garden (Figure 3), which grows on top of the Reading International Solidarity Centre (RISC). RISC is a Development Education Centre located in the middle of Reading (the largest town in the U.K.), and is used as an educational resource for sustainable development. Occupying an area of 200 m2, the garden is composed of dense plantings (including trees) of over 180 species of edible and medicinal plants and is fed by rainwater and composted waste from the centre. Remarkably, all of this is growing in just 30 cm of soil, and the whole project demonstrates what can be achieved by applying urban permaculture to “waste” – both the building itself, which had fallen into disuse, and its accompanying roof-space. It is important to apply permaculture in urban environments, since more than half of the global population lives in towns and cities, which it has been concluded must become places of food production. In addition to the greater preservation of the soil quality than is the case on industrialised farms, the more food that is grown locally, the less needs to be imported from across the country and indeed the wider world, thus saving on oil for transportation fuels. It has been estimated that just 30% of the global urban area would be required to produce all the vegetables consumed by urban dwellers. While there are impressive energy-efficient designs for buildings, e.g. passivhaus, it is not a practical proposition to simply raze our existing towns and cities to the ground and build-up again from scratch. Rather, we need to work within the framework that we have, i.e. the urban environment. Thus, it is necessary to incorporate permaculture designs within the existing urban infrastructure, which minimise waste by cycling resources, so to retain them within the “system” as long as possible (in the manner of how water and nutrients are cycled in a natural system, such as a forest). In addition to growing food in urban space, such actions as draught-proofing and thermally insulating existing building stock, and living/working on a more local scale, would serve well to cut overall energy use.

Holistic Planned Grazing
The practice of “Holistic Planned Grazing” was inaugurated as a means to combat desertification, and involves moving single herds containing thousands of cattle or sheep around on grassland, in an effort to mimic the behaviour of grazing animals in the wild, where they move in large groups (to protect themselves against predators), and graze one patch intensively, before moving on elsewhere. In this way, the grassland has time to recover completely, before it is grazed again, which benefits both the soil and the wildlife, and the animals’ manure is more evenly distributed, while their hooves incorporate more organic matter into the soil. The growth of longer grass provides better ground cover and a more extensive root mat, so that rainfall is better infiltrated into the soil, which leads to decreased flooding, less drought and the recharge of depleted groundwater systems (aquifers). This approach is of particular benefit for restoring grasslands (Fig. 4) in semi-arid or arid climates (“brittle environments”) and contrasts with the more conventional approach of removing animals from the land.

Further Reading.
Rhodes, C.J. (2017) “The Imperative for Regenerative Agriculture,” Science Progress, 2017,100, 80.
Rhodes, C.J. (2015) “Permaculture: Regenerative – Not Merely Sustainable,” Science Progress, 98, 403.
Rhodes, C.J. (2014) “Soil Erosion, Climate Change and Global Food Security: Challenges and Strategies,” Science Progress, 97, 97.
Rhodes, C.J. (2012) “Feeding and Healing the World: Through Regenerative Agriculture and Permaculture,” Science Progress, 95, 345.

Figure 1. Chikukwa Project (Zimbabwe).  “Before” in 1991: Bare hillsides and soil erosion, with consequent food and fuel shortages. Credit: Terry Leahy.

Figure 2. Chikukwa Project (Zimbabwe). “After” in 2005: Houses nestling among orchards, bunds with vetiver grass in the cropping fields, and extensive woodlots. Credit: Terry Leahy.

Figure 3. Trees... growing on a roof, in just 30 cm of soil! The weight might be an issue, however... 100 tonnes of “stuff”! Credit: Karen Blakeman.

Figure 4. Holistic Managed Grazing. A herd of cattle within a grassland landscape. Credit: Justin Jerez.

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