Julius Reiff

• Since its emergence approximately 10 000 years ago, agriculture has formed human lifestyle and facilitated the rise of complex civilizations. At the same time it led to the development of social inequality and allowed the overexploitation of natural resources. These processes in combination with climatic changes and a growing population resulted in the collapse of various advanced civilizations in human history. Today, we face a similar situation with a climate change for which we ourselves are responsible, despite our ability to understand what led to the collapse of past civilizations and to predict future developments. Modern industrial agriculture largely contributes to threatening environmental issues like climate change, soil degradation and biodiversity loss. Agroecology and permaculture have emerged as sustainable alternatives. While agroecology is a well-established scientific discipline, permaculture focuses on the conscious design of resilient agroecosystems that mimic nature. The second chapter reviews the scientific basis of permaculture's design principles, as proposed by co-founder David Holmgren. We find that permaculture not only builds on scientific evidence but also aligns with agroecological principles and offers additional guidelines for creating resilient farming systems. However, empirical evidence supporting permaculture’s benefits has been sparse. Therefore, we conducted two studies on commercial permaculture sites in Central Europe to examine the effectiveness of permaculture in both environmental sustainability and crop productivity. The first study examined a wide range of soil and biodiversity indicators on nine permaculture sites. The study found that permaculture sites had 27% higher soil carbon storage, 20% lower soil bulk density, and a 201% increase in earthworm abundance compared to direct control fields of predominant industrial agriculture. Additionally, levels of various soil macro- and micronutrients were higher on permaculture sites, indicating better conditions for crop production. Species richness for vascular plants, earthworms, and birds was also significantly higher on permaculture sites, with increases of 457%, 77%, and 197%, respectively. The second study, focused on the crop productivity of eleven permaculture sites. Using the Land Equivalent Ratio (LER) as an index, the study found that the yields from permaculture sites were comparable to those of industrial agriculture. Specifically, the LER for permaculture was 0.80 ± 0.27 when compared to total German agriculture and 1.44 ± 0.52 when compared to German organic agriculture, both with no significant difference to 1. Together, these studies suggest that permaculture not only offers environmental benefits but also holds promise in terms of crop productivity. These findings align well with global initiatives such as the "4 per 1000" initiative, the United Nations Decade on Ecosystem Restoration and the United Nations Sustainable Development Goals. Despite promising results, variability in outcomes suggests the need for further research to understand the complex factors influencing permaculture's effectiveness. Further, we advocate for a multi-dimensional approach to large-scale implementation, involving financial restructuring, educational reforms, and the initiation of flagship projects. Given the urgency of environmental crises, we argue that immediate action is imperative, with research serving as a tool for continuous improvement rather than a prerequisite for action.