Developing a suite of novel land conditioners and plant fertilizers from the waste streams of biomass energy generation

土壤提供、支持和调节环境中的基本过程，包括养分循环、植物生长，并对确保大气的纯度以及水的供应和质量产生重大影响。通过提供这些生态系统服务，维持了至关重要的全球生物多样性，并最终维持了人类的生计。然而，通过密集的农业做法，如过量施用磷肥和氮肥，对土壤的开发已导致土壤退化，从而降低土壤肥力，威胁未来的全球粮食安全。磷是作物生长所需的不可再生的重要元素，农业现在几乎完全依赖于维持目前的粮食生产水平。磷的提取和加工也对环境极具破坏性，并且来源于不可再生的来源，对该来源的需求正在迅速增加，并且在所需的量中没有可用的替代品。氮肥的生产也是一个高度能源密集和不可再生的过程，与化石燃料的价格和可用性密切相关。随着全球人口预计到2050年将达到90亿，人类迫切需要平衡对能源和自然资源日益增长的需求，以及生态系统及其提供的重要服务的可持续管理。如果管理得当，生物能源部门提供了一个独特的机会，可以部分解决农业，能源生产和废物处理所面临的挑战。气化、焚烧、生物质锅炉和厌氧消化（AD）是目前用于将各种生物质和废弃生物质衍生燃料转化为可再生能源的主要技术。这些技术本身产生的副产品，如生物质热转化产生的灰分（富含磷）和AD产生的亚硝酸盐（富含氮），具有互补的营养价值和特性，有利于它们用作土壤改良剂和肥料。然而，这些废物流通常被低估，并且经常以成本进行处置，由于缺乏定量证据以在适当规模或跨科学学科上做出明智的决策，因此很少考虑环境健康的最佳实践。生物能源废物处理是一项重要的技术，旨在为农业实践提供安全和可持续的营养来源，从而减轻对自然资源的压力，并解决生物能源废物处理面临的一些挑战。（一）对各种固态物质和灰烬以及由此产生的混合物进行物理和化学测试，以考虑将其作为土壤改良剂。(ii)在温室中仔细控制的条件下，比较选定的肥料、灰烬和混合物与传统肥料对土壤性质、植物生长（冬小麦和豌豆）和养分循环的影响。(iii)在密集的温室研究之后，将对最有前途的混合土壤改良剂进行测试，并将其与冬小麦和豌豆两个生长季节的田间常规肥料施用进行比较。(iv)与环境署合作，探讨如何开发最有前途的土壤改良剂，用于农业，作为传统肥料的真正替代品。在温室和田间条件下对选定的作物类型进行广泛测试后，最终混合的灰和固态产品将适用于农业环境，作为传统肥料的直接替代品。好处包括减少对磷肥和氮肥的依赖，以及保持土壤的物理化学完整性，从而有助于长期粮食安全。

Soils provide, support and regulate fundamental processes in the environment, including nutrient cycling, plant growth, and have a strong influence on ensuring purity of the atmosphere, as well as water supply and quality. Through the delivery of these ecosystem services, vital global biodiversity and, ultimately, the sustenance of the human population is maintained. However, exploitation of soils through intensive agricultural practices such as the over application of phosphorus and nitrogen fertilisers, has resulted in their degradation and, as a result, a diminishment of soil fertility, threatening future global food security.Phosphorus is a vital, non-renewable element required for crop growth, upon which agriculture is now almost entirely dependent to maintain current levels of food production. The extraction and processing of phosphorus, is also extremely environmentally damaging, and originates from a non-renewable source for which demand is rapidly increasing with no alternative available in the volume required. The production of nitrogen fertiliser is also a highly energy intensive and unstainable process, is tied strongly to the price and availability of fossil fuels. As the global population is expected to reach 9 billion by 2050, humanity faces an urgent need to balance an ever increasing demand for energy and natural resources, with the sustainable management of ecosystems and the vital services that they provide.If managed correctly, the bioenergy sector presents a unique opportunity to, in part, address the challenges facing agriculture, energy generation, and waste disposal. Gasification, incineration, biomass boilers and anaerobic digestion (AD) are currently the dominant technologies being deployed to convert a wide range of biomass and waste biomass derived fuels into renewable energy. The by-products generated from these technologies themselves, such as ash (rich in phosphorus) from biomass thermal conversion and digestate (rich in nitrogen) from AD, have complimentary nutrient values and properties conducive to their use as soil conditioners and fertilisers. However, these waste streams are a typically undervalued, and frequently disposed of at a cost, with little consideration of best practice for environmental health due to the lack of quantitative evidence on which to base informed decisions at appropriate scales or across science disciplines.It is the overarching aim of this research to mix ash and digestate waste materials to form a new, safe and sustainable source of nutrients for agricultural practice, thereby reducing pressure on natural resources and to address some of the challenges facing bioenergy waste disposal. This will be achieved through the following:(i) To physically and chemically test the individual digestates and ashes and the resulting mixtures for consideration as soil amendments.(ii) To compare the impact of selected digestates and ashes and mixtures against traditional fertilisers on soil properties, plant growth (winter wheat and pea) and the cycling of nutrients under carefully controlled conditions in glasshouses.(iii) Following intensive glasshouse studies, the most promising of the blended soil amendments will be tested and compared to conventional fertiliser application in the field over two growing seasons for winter wheat and pea.(iv) To engage with the Environment Agency about the way forward in developing the most promising soil amendments for use in agriculture as genuine alternatives to conventional fertiliser application.Following extensive testing on selected crop types both in glasshouses and under field conditions, the final blended ash and digestate product(s) will be applicable for use in an agricultural setting as a direct substitute for traditional fertilisers. Benefits include a reduced dependence on phosphorus and nitrogen fertilisers, as well as maintenance of the physical chemical integrity of soil, thereby aiding long-term food security.