Table 2.

Circular agriculture principles

Principles	Explanation	Implications for agriculture
1. Safeguard the health of our agro-ecosystems	Ecosystem stocks (like soils and forests) must not be used beyond their regenerative capacity and sinks (like the air) must not be polluted	Avoid emissions to the environment (e.g. CO2, N, P) Cease the use of finite resources such as fossil fuels, phosphate rock Protect and regenerate biodiversity and soil health
2. Avoid the production of non-essential products and the waste of essential resources	Because materials can never be fully recycled and production processes inevitably create pollution, unnecessary production and losses must be prevented	Prevent food waste and overconsumption Prevent nutrient losses Prevent resource-intensive inputs like synthetic fertiliser
3. Prioritise the use of natural resources for basic human needs	Natural resources like biomass and land are scarce and should be used effectively. This implies that biomass should be used for essential needs first	Land and biomass should be used primarily to feed humans instead of farm animals Farm animals should only be fed non-human edible biomass
4. Recycle by-products of the agro-ecosystem	Even if losses and waste are avoided (principle 2), the production of food comes with residual streams such as manure and crop residues. These should be reused in the food system at their highest utility	Use residual streams to feed farm animals, to fertilise soils and to produce biomaterials Only use materials that are not safe for recycling to produce energy
5. Entropy, or minimise and avoid the use of energy and use renewable energy sources	Recycling of nutrients and materials inevitably costs energy, therefore energy use should be minimised in addition to transitioning to renewables	Minimise and avoid energy use Use renewable energy sources

Based on Muscat et al. (2021)