## 1 Introduction  
European farming systems are among the most efficient production systems in the world [1]. However, these systems are often input-intensive as they consume large quantities of mineral fertiliser, water, fuel and pesticides [2]. In Europe, 46% of the total N applied to agricultural soil comes from mineral fertiliser [3]. A transition towards sustainable agriculture is needed, not only to reduce the environmental impact of agricultural systems, but also to become more resilient to economic and societal challenges such as fluctuating production prices, changing consumer behaviour, and extreme weather events. Awareness of the urgency for sustainable and resilient farming systems has increased among policy makers, businesses, and the scientific community [4]. The European Commission emphasises this by the large number of policy initiatives that were recently established: the EU Green Deal, Farm to Fork Strategy, Chemicals Strategy for Sustainability, New EU Strategy on Adaptation to Climate Change, Organic Farming Action Plan, Zero Pollution Action Plan for Air, Water and Soil, New Soil Strategy, Fertilizing Product Regulation revision, and the Fit for 55 Climate Package.  
One way to stimulate the transition towards sustainable and resilient farming systems is circular agriculture because it aims to minimise external inputs and negative discharges to the environment, and to close nutrient cycles. Therefore, it allows crop and livestock production without the depletion of non-renewable sources and harming the environment. In 2018, the European agricultural sector consumed 10.2 million tonnes of mineral nitrogen (N) fertiliser and 1.1 million tonnes of mineral phosphorus (P) fertiliser [5]. Reducing these numbers by using technologies that valorise biowaste into bio-based fertiliser (BBF) products can stimulate circularity [6; 7; 8; 9; 10]. Different techniques have been developed for the recycling of nutrients from biowaste [11]. For example, liquid and solid separation can be carried out through centrifuge, screw or belt press, and pressurized membrane filtration techniques such as microfiltration, ultrafiltration, or reversed osmosis can be used to refine the products [11; 12]. BBF products that meet the criteria of being referred to as recovered nitrogen from manure (RENURE) are safe to use as N fertiliser [13]. However, criteria define quality and handling rules that BBF should comply in order to be classified as RENURE [13]. This process of being classified as RENURE product is still ongoing for several BBFs.  
The adoption of (potential) RENURE products in the agricultural sector depends on collaborations between the biowaste producers (e.g., pig farmers), biowaste processing industry, and end users of BBFs. This study collaborated with all three stakeholders and in combination with laboratory and pot and field experiments, this study provides a unique and complete picture of the potential adoption of the tested BBFs. This way of analysing the adoption of BBFs is important because each stakeholder has different interests [6]. For example, factors influencing the decision of end users to adopt BBFs depends especially on the agronomic efficiency of BBFs [14]. These end users are questioning whether the agronomic efficiency of refined or less refined BBFs differs. Therefore, the hypothesis of this study is to test whether refined BBFs perform environmentally and agronomically better compared with less-refined BBFs. This study aims to analyse the environmental and agronomic effect of using BBFs that differ in refinement level.