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

在中国和印度这两个地球上人口最多的国家，以及东南亚、非洲和南美洲的发展中国家，红壤分别覆盖了20%的面积。它们形成于亚热带气候，在那里雨水的过度淋洗造成了贫瘠、不稳定的土壤，非常容易受到管理不善、气候变化和酸雨等污染的影响。在中国，红壤养活了大约40%的人口，这是通过密集使用化肥来提高作物产量实现的。这种耕作制度是不可持续的；进入地下水、淡水和大气的化肥对环境构成重大威胁，集约化耕作造成的土壤退化可能导致每年在季风性强降雨期间从一公顷土地侵蚀成水道的土壤达数十吨。红壤农业管理影响到依赖红壤谋生的当地农民，影响到需要红壤作为食物的周围人口，中国因为国家粮食生产的依赖，以及由于红壤覆盖的面积、对粮食生产的重要性和巨大的环境足迹而影响全球。尽管对红壤进行了广泛的研究，特别是与农业可持续管理相关的研究，但人们对红壤临界区各个受影响方面的综合影响以及更广泛的环境影响知之甚少。在这项提案中，我们采用临界区方法，超越土壤过程，涵盖上面的大气、下面的地质和地下水、周围的淡水和植被。根据定义，临界区是地球表面不断演变的边界层，岩石、土壤、水、空气和生物在这里相互作用。两个必不可少的组成部分是交付所必需的。首先，我们有孙家临界区观测站的主要优势，这是中国自2002年以来唯一收集水土数据的国际临界区观测站。其次，我们组建了一支由中国和英国科学家组成的团队，他们将土壤科学方面的一系列专业与大气、地质、水文和农学相结合。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，并提出了培训和联合职位，将在中国发展这一能力。我们通过纳入过去未包括的地下和大气过程，建立在现有孙家CZO监测的基础上。实验室和野外的进一步实验将使我们能够探索气候变化、缺水和酸雨等环境威胁的影响。我们涉及风化矿物的过程，这些矿物如何与生命相互作用形成土壤，以及我们如何在土壤进化中优化这些过程，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的水文和侵蚀影响的理解。对孙家CZO和其他红壤地区这些过程的详细监测提供了数据，为我们建立生态系统过程模型提供了信息。这一过程极大地得益于红壤临界区监测数据集，该数据集将持续近20年。该项目产生的新科学，特别是模型输出，为中国关于红壤管理的决策提供了宝贵的数据。我们为项目合作伙伴提供跨学科科学方面的培训，这对CZO的研究至关重要，并将有利于中国团队的研究能力。此外，我们还为中国队带来了地面建模方面的新技能。再加上我们在红壤上生产更可持续的粮食的预期成果，我们的培训和政府机构的参与确保了经合组织从这个项目中提供官方发展援助。

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.