The loss of biodiversity in agricultural landscapes has been dramatic over the past few decades with negative trends persisting. Organic farming has received widespread recognition in the scientific and politic fields for its environmental benefits, although the proportion of land cultivated organically is still small and the extent to which organic farming contributes to the promotion of biodiversity is viewed controversially. We present a critical, quantitative review of 98 mainly peer-reviewed papers selected from 801 studies in temperate climate zones published over the period 1990–2017. We quantified differences in the species richness and abundance of selected flora and fauna groups. In total, 474 pairwise comparisons that compared organic and conventional farming systems were considered. Overall, organic farming showed higher species richness or abundance in 58% of the pairs. No differences were found for 38%, 4% indicated negative effects from organic farming. The average (median) species numbers of flora on arable land were 95% higher under organic management as well as 61% higher for seedbank and 21% higher for field margin vegetation. For field birds, the species richness was 35%, and the abundance was 24% higher in organic farming; for insects, the corresponding values are 22% and 36% and for spiders 15% and 55%. Our study underlines that organic farming can play an effective role in acting against the loss of biodiversity. Future research should focus on the combined effects of landscape structures and organic farming, the effect of large-scale organic farming, as well as on the correlation of species diversity and production parameters. To meet the systems’ representativeness, even more strict selection criteria need to be applied in further analysis.

Although scientists have been researching the impacts of organic agriculture on the environment and animal welfare for decades, the conclusions drawn by the scientific community remain controversial. Against this background, this paper provides a comprehensive assessment of the benefits of organic farming in both areas by analysing results of all relevant scientific comparative studies between organic and conventional farming that have dealt with this topic over the last thirty years. So far, this study is the largest one of its kind and the first one that adds the aspect of animal welfare to a comprehensive array of impact categories. The systematic review of the scientific literature from pairwise comparisons found that organic management showed clear advantages over conventional management in the fields of environmental protection and resource conservation, which can be mainly explained by the system approach pursued in organic farming. No clear conclusion was drawn regarding animal welfare indicating that farm-specific management factors are of greater importance than the production system (organic vs conventional). Consequently, organic farming may contribute to solving current environmental and resource challenges and is rightly considered a key approach for sustainable land use. The positive effects should be further strengthened by decreasing the yield gaps between organic and conventional farming, i.e. by improving yields based on organic principles as well as by altering their relevance through changes in consumption as feed for livestock and food for humans.

Eutrophication caused by agriculture is an increasing ecological threat to the Baltic Sea. Modern, resource-efficient farming systems based on integrated plant and animal production, effective nutrient recycling and low external inputs can enhance multiple agro-ecosystem services, resulting in reduced pollution. Practical examples of such farming systems are not widespread. Therefore, the Baltic Ecological Recycling Agriculture and Society (BERAS) Implementation project aimed to foster this systemic shift. In this paper, agronomic strategies are described to improve nitrogen (N) efficiency for the conversion to ecological recycling agriculture (ERA). First, N farm gate balances of 22 farms in conversion are presented. They showed a large variation from −9 to 90 kg∙N∙ha⁻¹∙a⁻¹. Then, the use of guidelines and advisory tools to improve the nitrogen efficiency is described. The legume estimation trainer and nitrogen budget calculator help assess and optimize the nitrogen supply from legumes under farming conditions. The application of the crop rotation planning tool “ROTOR” guides advisors and farmers to identify agronomically and environmentally sound rotations. The tools can help overcome key agronomic constraints by implementing ERA. The necessity of accompanying measures from policy and the need to change food consumption patterns are discussed.