The circular economy
The circular economy concept concerns the creation of sustainable growth by maximising the efficiency of resource allocation and ultimately, producing more outputs from fewer inputs in a semi-closed system. In agriculture, there are opportunities to reuse outputs, such as waste, at all stages of the production process, and use them as inputs for other production chains.
The need for sustainable food systems and reduced waste is driving the development of innovative solutions that benefit both the environment and the economy. In many ways, the circular economy (CE) is returning to a traditional approach where all outputs have another use and supply chains are fully integrated. Within a CE system, waste created during the manufacturing process is reused and reintroduced as an input into the production cycle. This creates a semi-closed loop where resources are recycled, thus reducing the need to add more materials as well as making use of by-products. A closed loop, where all waste is reused within the production process, is the most desirable outcome for sustainability and could be the business model of choice for industry in years to come.
The CE might sound simple, but it involves a radical transition away from the predominantly linear model of today. In his 1966 thesis, The Economics of the Coming Spaceship Earth, the economist Kenneth Boulding first introduced the idea of a closed-loop economic system that integrates the reuse and recycling of used materials. Boulding argued that Earth should be viewed as a single spaceship, without unlimited resources or capacity to take unlimited pollution, with humans needing to adapt to living in a closed sphere.
Smart connections between plant and animal products
A circular agri-food system
In recent years, the CE has become a widely accepted model for sustainability, with particular relevance for the agri-food sector. With a growing global population, food and water security have spurred interest in new forms of agriculture that are less wasteful and more efficient. The flexible nature of CE within an agri-food system makes it an ideal framework that can be implemented in sectors as diverse as aquaponics, large-scale livestock rearing and arable crop production.
A circular agri-food system ensures a reduction in waste and decreases land-use and reliance on chemicals. A further study by the Ellen MacArthur Foundation projects that a CE-based agricultural system in Europe could cause a 45-50% drop in the use of fertilisers, pesticides and water, while the use of land, electricity, fuel and accompanying greenhouse emissions could also drop by up to 20%. This drop has been demonstrated by Dutch researchers, who are optimising resources through a closed-loop system that integrates vegetable production and livestock rearing. This system reduces the need for fertilisers while decreasing agricultural and livestock waste, as well as improving soil quality and crop yields by up to 70%.
Limited resources in island nations
For many Small Island Developing States (SIDS) a lack of local capacity to process waste means that the economics frequently favour a circular CE-inspired agricultural system, for which waste management and supporting infrastructure are key. Leota Kosi Latu, director general of the Secretariat of the Pacific Regional Environment Programme (SPREP) illustrated in 2018 the need for SIDS to protect resources by adopting a CE: “Poor waste management and inadequate control over highly polluting activities poses risks to the overall economic base of most Pacific island nations, i.e. tourism, agriculture and fisheries. These activities are very reliant on a clean environment. In the CE, innovation is the key. We need new technology, products, services and business models to enable the transition.”
As in any region, waste is an important issue for SIDS to address and SPREP is working towards implementing a CE across the Pacific that focuses on terrestrial waste management. Increased levels of ocean plastic pollution washing up on island shores are also giving cause for concern. Locals having very little control over this plastic washing in from overseas, but some are now looking for ways to use it as a resource – something being investigated by the Plastic Mining Cooperation.
Developing the tourist economy
Tourism is a vital economic sector for many SIDS, and the CE has a growing importance for the marketing of eco-tourism destinations. As part of a movement towards sustainable tourism in the Caribbean, eco-resorts are using circular agriculture to reduce their environmental impact and make the most of local produce.
The Ocean Spray eco-resort in Barbados uses the tropical rainforests surrounding it as the inspiration for a CE business based on agroforestry and permaculture, even inviting guests to forage for food as part of their experience. The hotel covers over 21 ha of terraces with over 80 different types of fruit trees and edible plants including coconuts, bananas, cocoa, coffee and pineapples, in addition to a flock of free-range chickens. Importantly, the resort strives to be zero-waste, as owner Mahmood Patel explains: “We are focused on taking land that has been undeveloped for over 100 years and are turning it into a food forest. We strive to keep everything in a cycle. We take all of our leaves and cuttings and put them back into the ground. We take dry coconut husks, put them in a chipper and bury them. We use the chicken and the goat manure as fertiliser. We take the eggshells, the coffee grinds and ‘green stuff’ from the restaurant and send them back up to the forest to fertilise the soil.”
Repurposing agriculture outputs
The city of Blantyre in Malawi has identified organic food waste as a major issue and an opportunity to benefit the community. By collecting, sorting and composting waste in a purpose-built recycling centre, the local government developed a system at Limbe Market to convert the approximately 1 t of organic waste generated into high-grade compost that is then sold to consumers. However, the city is limited by a lack of transport and logistical infrastructure that prevents them from reaching other communities and sharing their knowledge.
In South Africa, multinational company AgriProtein has tackled organic waste by using insects to create 100% organic fish and animal feed, oils and soil fertiliser. The company breeds black soldier flies, the larvae of which rapidly break down organic waste while increasing their weight over 200 times in a 10-day period. The core product is made from dried and defatted insect larvae that are ground into a high-protein meal suitable for a wide range of farmed fish and livestock. Additionally, the oil extracted from the fat of whole dried larvae can be blended with a variety of animal feeds. Finally, the larval residue is blended with compost to create a fertile soil enrichment. These multiple output streams ensure that AgriProtein produces little waste during manufacturing and promotes sustainable farming practices. The company currently has farms in Cape Town, Durban and Johannesburg with plans to expand its business at a rate of two standard factories a month across the continent. Each factory will be capable of processing 250 t of waste per day, from which they can create 5,000 t of meal and 2,000 t of oil per year.
Circular agriculture has the potential to be a flexible system that can
be adapted for any location or sector. With an increasing need to reduce waste
and use limited resources efficiently to feed an ever-growing world population,
the need for a more sustainable approach is critical. Creating a CE can not
only maximise the allocation of limited resources without further harming the
environment, but also creates a more efficient economic system, with ultimately
more food created per unit input.