WHyGro-in-Me: Waste-based Hybrid Growing Media for PACE Horticulture using biobased polyurethane binders and biowaste filler

随着保护地栽培的爆炸性增长，对栽培基质的需求也在增加。这一趋势预计将在未来持续下去，到2050年，媒体产量预计将增长420%。尽管传统媒体的生产预计会增长，但预计市场仍存在缺口，每年有6500万立方米的缺口将被“新”增长媒体所占据[1]。我们的团队一直专注于使用聚氨酯泡沫（PUF）作为生长介质，我们已经证明植物生长可以根据泡沫特性进行建模，并且PUF基质在产量方面与岩棉相匹配[2，3，4]。虽然原始PUF显示出作为水培生长介质的前景，但由于疾病问题，在生长季节后难以重复使用，在使用之间需要昂贵且耗时的蒸汽清洁（类似于其他基质）[5]。另一方面，常规混合物通常含有大量的泥炭基组分，并且随着日益增长的媒体行业寻求"去泥炭"，需要找到替代品。已经提出了许多成分，并取得了一定的成功，包括堆肥、椰壳纤维、木屑、木纤维、生物炭和稻壳。这些成分通常是生物废弃物产品，相对于泥炭等有限资源而言，具有环境优势，但由于其有机性质和不同来源，其物理和化学性质存在差异[6]。这种变异性导致了生长的变异性，这是专业种植者的噩梦。这是一个全球性的挑战，需要一个全球可行的、以科学为主导的解决方案。该项目旨在解决减少PACE生产对环境影响的挑战，同时可持续地提高产量，方法是使用来自食品生产平行行业的生物废弃物填料（锯末、木纤维、酒糟、羊毛、棉织物等）合成优化的均质生长介质。我们的目标是：新型生物基聚氨酯预聚物（bPUP）的合成和表征（我们的工业合作伙伴Vita Cellular Foams将提供bPUP前体和PUP用于测试）使用bPUP粘合生物废弃物填料并生成均匀的混合生物基生物废弃物生长介质。使用实验设计（DoE）和基于建模的方法，通过开发具有优化的嵌入式营养成分的作物和系统特定"生长介质配方"，优化这些介质，以提高作物产量。材料表征和初始作物生长试验在谢菲尔德大学完成，而我们的工业合作伙伴智能生长解决方案（IGS），将使用其最先进的垂直农场技术进行工业试验。使用目标生物降解探索生命终结途径，通过结合特定的生物降解地点，对生长介质进行堆肥和机械回收。该项目有可能产生重大的科学成果，通过新型bPUP的合成和表征，以及为PACE园艺开发作物和系统特定的"培养基配方"，取得了进展。这项研究还可能带来商业化机会，促进经济发展。此外，该项目可以帮助建立一个以英国为基础的专业领域，在不断增长的媒体发展和特点，解决目前缺乏代表性，在这一领域。

With the explosive growth in protected cultivation, there has been an increased demand for growing media. This trend is expected to continue in the future, with growing media production predicted to grow by 420% by 2050. Despite the expected growth in conventional media production, there is still predicted to be a shortfall in the market, with a gap of 65 million cubic metres per year to be taken up by "new" growing media [1]. Our team have been focused on the use of polyurethane foams (PUF) as a growing media where we have shown plant growth can be modelled based on foam properties and PUF substrates have matched rockwool in terms of yield [2,3,4]. While virgin PUF shows promise as a hydroponic growing medium, it is difficult to reuse after a growing season due to disease concerns, requiring costly and time-consuming steam cleaning between uses (similar to other substrates) [5].Conventional mixes, on the other hand, often contain a large peat-based component and as the growing media industry looks to "de-peat", alternatives will need to be found. Many components have been suggested and used to some success, including compost, coco coir, wood chips, wood fibre, biochar, and rice hulls. These components, often biowaste products, bring environmental advantages over finite resources such as peat but suffer from variability in terms of physical and chemical properties due to their organic nature and varying sources [6]. This variability leads to variability in growth, a professional grower's nightmare. This is a global challenge that will require a globally viable, science led solution.This project looks to address the challenge of reducing environmental impacts of PACE production, whilst sustainably increasing yields, by synthesising optimised homogeneous growing media using biowaste based fillers from parallel industries to food production (sawdust, wood fibres, spent grain, sheep wool, cotton fabric, etc.) homogenised and bound together using novel biobased and biodegradable polyurethane prepolymers (bPUP) with tunable embedded fertiliser (Figure 1).Our objectives are:Synthesis and characterisation of novel biobased PUP (Our industrial partner, Vita Cellular Foams, will supply bPUP precursors and PUP for testing).Use of bPUP to bond biowaste fillers and generate homogeneous hybrid biobased-biowaste growing media. Use of a design of experiments (DoE) and modelling based approach to optimise these media to increase crop yield by developing crop and system specific "growing media recipes" with optimised embedded nutrient profiles.Material characterisation and initial crop growth trials completed at the University of Sheffield, while our industrial partner, Intelligent Growth Solutions (IGS), will conduct industrial trials using their state-of-the-art vertical farm technology.Exploration of end-of-life pathways using targeted biodegradation, composting and mechanical recycling of growing media by incorporating specific sites for biodegradation.This project has the potential to generate significant scientific advancement through the synthesis and characterisation of novel bPUPs, as well the development of crop and system specific "media recipes" for PACE horticulture. There is also likely to be economic development by commercialisation opportunities arising from this research. In addition, the project can help establish a UK-based area of expertise in growing media development and characterisation, addressing the current lack of representation in this field.