## 1 Introduction  
The latest World Food Security Outlook suggested that global food security should be expected to stabilize in 2024. However, the threat of food insecurity still looms over nearly one billion people [1]. For decades, and at present especially, many questions have been raised about how we can continue to feed the growing global population [2, 3]. The agriculture industry has always been the backbone of global food production and fertilisers play a critical role in maximizing crop yields. Achieving optimal crop yields while minimizing environmental impact is a key goal for farmers [4]. A large part of this effort is proper fertilization, which involves the precise combination of nutrients. This has resulted in further development of the fertiliser industry and the production of commercial fertilisers. Fertilisers provide nutrients that are essential for the development and growth of plants [5, 6, 7, 8]; however, recently, they have acquired somewhat negative connotations and a mixed reputation. This view has been formed as a result of excessive use, and its negative impact on soil properties and human health [9, 10, 11, 12]. Today, suppliers and fertiliser manufacturers are attempting to use fertilisers more efficiently and are focusing on maintaining the balance of soil nutrients and microorganisms for specific crop soils [13, 14, 15, 16]. According to the World Bank, global waste generation is expected to increase by 70% by the year 2050 [17]. Recycling waste into fertiliser is often a part of broader initiatives to promote a circular economy and reduce the environmental impact of waste disposal. According to a report by the Food and Agriculture Organization (FAO), the global volume of food wastage is estimated to be 1.6 Gt of \"primary product equivalents\", while the total wastage for the edible part of food is 1.3 G [18]. The process typically involves converting organic waste, such as plant residues, plant and animal by-products (bone meal, fish meal), food scraps, and other food waste into nutrient-rich fertilisers through composting or other conversion methods [19; 20; 21; 22]. The circular economy concept emphasizes the importance of closing the loop in the production-consumption cycle by reusing organic waste to create valuable resources (fertil) rather than sending it to landfills [23]. Recycling waste into fertilisers helps divert organic waste from landfills, thus reducing the overall volume of waste and mitigating the methane emissions associated with decomposition; using organic fertilisers derived from recycled waste in improving soil structure, fertility, and water retention contributes to sustainable and regenerative agricultural practices; they promote plant growth and reduce the need for synthetic fertilisers [24]. One simple and traditional solution to waste management lies in the transformation of organic waste into compost [25; 26; 27] or vermicompost [28; 29; 30]. The resulting compost can be used to enhance soil fertility, reduce the need for chemical fertilisers, and promote sustainable agriculture practices. Another popular and easily implemented method of waste utilization is pyrolysis. Pyrolysis involves thermal decomposition of organic waste in the absence of oxygen, resulting in the production of biochar, bio-oil, and non-condensable gases. While biochar serves as a carbon-rich soil amendment and fertiliser, other components are not suitable for fertilization and must be further recycled [31; 32; 33]. Fertilisers, as products with a higher added value, are supplied in liquid form as solutions, or in a solid form. Solid fertilisers are created through bulk pressing, profiling, or granulating [34; 35]. These granules combine various raw materials with essential micronutrients to create balanced and nutritionally rich granules and therefore are a key factor in ensuring healthy plants, exceptional growth, disease resistance, and optimized yields. Fertiliser granulation is a process where fertiliser particles become attached to each other through agglomeration.