WP 4: Soil Impacts and Leaching

Agricultural soils account for considerable nitrogen leaching to groundwater. In China, especially in the Beijing−Tianjin−Hebei (BTH) region, this exceeds 50%. This poses a risk of adverse health effects such as methaemoglobinaemia in infants and gastric and oesophageal cancers for both urban and rural populations. In this work package, we will quantify regional-scale N leaching from agricultural soils at high spatial resolution and assess their potential health risks, as well as to optimize agricultural management practices to mitigate health risks.

• Based on massive surveys related to agricultural managements and county-scale statistic registers (Zhou et al., 2014), we will compile a high resolution and climate-adaptive N inputs and irrigation dataset, such the synthetic fertilizers, manure, crop residues, human excreta, and irrigation amounts. Combining the datasets with local schemes of fertilization and irrigation, we finally develop a high-resolution and real-time N inputs and irrigation datasets from targeted cities or regions.
• Both land surface model (ORCHIDEE-CROP, Wang et al., 2017) and flux upscaling approach (Gao et al., 2016, Hou et al., 2017) are applied for the estimates that are constrained by multi-source observations of N leaching fluxes. Regional N leaching at different soils and the associated N flow in aquifer groundwater will be quantified under different agricultural management and climate change.
• Based on probabilistic effect-response functions, we will assess negative effects of N applied in urban and rural agricultural soils on human and livestock health, and implement N inputs and irrigation datasets from different scenarios of agriculture management and climate change to models, thereby quantifying how they affect the N-related concentrations in the urban groundwater.