Red Soil CZ: From natural to anthropogenic evolution of Red Soil and its impact on ecosystem function in the Critical Zone

红土覆盖了世界上人口最多的中国和印度各20%的土地，以及东南亚、非洲和南美洲的大片发展中国家。它们形成于亚热带气候，在那里，雨水的过度浸出产生了贫瘠、不稳定的土壤，极易受到管理不善、气候变化和酸雨等污染的影响。在中国，红壤供养着大约40%的人口，这是通过大量使用化肥来提高作物产量而实现的。这种农业系统是不可持续的；进入地下水、淡水和大气的肥料对环境构成了严重威胁，而集约化耕作导致的土壤退化每年可能导致每公顷土地上数十吨的土壤在雨季和春雨期间被侵蚀到水道中。红壤农业管理影响到当地依靠红壤维持生计的农民，影响到需要红壤获取食物的周边人口，影响中国是因为红壤对国家粮食生产的依赖，影响全球是因为红壤覆盖的面积、红壤对粮食生产的重要性和巨大的环境足迹。虽然对红壤进行了广泛的研究，特别是与农业可持续性管理有关的研究，但对关键地带各受影响方面的综合影响以及更广泛的环境影响了解甚少。在这个方案中，我们采用了一个关键区域的方法，超越了土壤过程，涵盖了上面的大气、下面的地质和地下水、周围的淡水和植被。根据定义，临界带是地球表面岩石、土壤、水、空气和生物相互作用的不断演化的边界层。两个基本组成部分对交付至关重要。首先，我们的主要优势是孙家临界带观测站（CZO），这是中国唯一一个自2002年以来收集土壤和水数据的国际CZO。其次，我们组建了一个由中英两国科学家组成的团队，他们在土壤科学、大气科学、地质科学、水文科学和农学等方面具有广泛的专业知识。英国团队填补了中国合作伙伴在陆地环境建模方面的技能差距，并提出了在中国发展这一能力的培训和联合职位。我们在现有孙家CZO监测的基础上，纳入了过去未包括的地下和大气过程。在实验室和实地进行的进一步实验将使我们能够探索气候变化、水资源短缺和酸雨等环境威胁的影响。我们涵盖了风化矿物的过程，这些矿物质如何与生命相互作用形成土壤，以及我们如何优化土壤进化中的这些过程，以造福环境和粮食安全。这些过程增强了我们对不同管理措施对红壤水文和侵蚀影响的理解。在孙家CZO和其他红壤地区对这些过程的详细监测为我们的生态系统过程建模提供了数据。该过程极大地受益于红壤关键区域监测数据集，该数据集将在项目结束时跨越近20年。在这个项目中产生的新科学，特别是模型的产出，为中国关于红壤管理的政策决策提供了有价值的数据。我们为项目合作伙伴提供跨学科科学培训，这对CZO研究至关重要，并将有利于中国团队的研究能力。此外，我们还为中国团队带来了陆地建模方面的新技能。再加上我们的目标是利用红壤生产更可持续的粮食，我们的培训和政府机构的参与确保了该项目提供经合组织官方发展援助。

Red soils cover 20% of each of China and India, the most populated countries on earth, as well as large areas of developing countries in southeast Asia, Africa and South America. They form in sub-tropical climates where excessive leaching from rainwater has produced an infertile, unstable soil that is very vulnerable to mismanagement, climate change and pollution such as acid rain. In China, red soils support about 40% of the population, made possible through the intensive use of fertilisers to boost crop yields. This farming system is unsustainable; fertilisers reaching groundwater, freshwater and the atmosphere pose a significant environmental threat, and soil degradation through intensive cultivation can result in tens of tonnes of soil being eroded each year from a hectare of land into water courses during the intensive monsoonal, spring rains. Red soil management for agriculture affects local farmers who depend on them for their livelihood, the surrounding population who need them for food, China because of dependence for national food production and globally because of the area red soils covers, their importance for food production and the large environmental footprint.Although extensive research has studied red soils, particularly related to management for agricultural sustainability, the integrated effects of various affected aspects of the critical zone, as well as the wider environmental impacts are poorly understood. In this proposal we adopt a critical zone approach, to reach beyond soil processes to encompass the atmosphere above, geology and groundwater below, surrounding freshwater and vegetation. By definition, the critical zone is the constantly evolving boundary layer at the surface of the earth where rock, soil, water, air and living organisms interact. Two essential components are essential for delivery. First, we have the major advantage of the Sunjia Critical Zone Observatory (CZO), the only international CZO in China where soil and water data have been collected since 2002. Second, we have assembled a team of Chinese and UK scientists who integrate a range of specialisations in soil science, with atmospheric, geological, hydrological and agronomical sciences. A skill gap identified amongst the Chinese partners in terrestrial environmental modelling is filled by the UK team, with training and joint positions proposed that will develop this capability in China.We build on existing Sunjia CZO monitoring by incorporating subsurface and atmospheric processes not included in the past. Further experiments in the lab and the field will allow us to explore impacts of environmental threats such as climate change, water scarcity and acid rain. We span from processes involved in weathering minerals, how these minerals interact with life to form soils, and how we can optimise these processes in soil evolution for the benefit of the environment and food security. These processes then enhance our understanding of hydrological and erosion impacts in red soils induced by different management practices. Detailed monitoring of these processes in the Sunjia CZO and other red soil areas provides data that inform our modelling of ecosystem processes. This process benefits immensely from a critical zone monitoring data-set for red soils that will span almost 20 years by the end of the project.The new science generated in this project, particularly the modelling outputs, provides valuable data for policy decisions in China about the management of red soils. We provide training to project partners in interdisciplinary science that is essential to CZO research and will benefit the research capabilities of the Chinese team. Moreover, we bring new skills to the Chinese team in terrestrial modelling. Coupled with our intended outcome of more sustainable food production from red soils, our training and government agency engagement ensures delivery of OECD Official Development Assistance from this project.