Modelling nutrient acquisition by crops with specific consideration of biopores

要定量了解土壤结构、土壤营养库、根构型结构与作物从下层土壤中吸收水分和养分之间的相互作用，需要考虑到所涉及的过程的复杂性，包括地上部生长、根系发育、土壤水分动态和土壤养分周转。数学模型为定量描述植物-土壤系统中的水分和养分动态提供了一种有用的手段。该提案的中心假设是，对作物从底土中获得养分的模拟不仅要考虑具有特定根系的作物类型，而且要考虑土壤结构，特别是生物孔。我们假设，考虑生物孔密度和质量以及土壤水分状况对底土养分周转和可及性的影响，将改进田间尺度上作物吸收养分的动态模拟模型，为今后改进农艺管理和作物提供更好的基础。特别强调N和P的获取与土壤水分条件和养分需求的相互作用。该项目采用两室法，在模拟框架SIMPLACE内开发了土壤基质和土壤生物孔内N和P的周转和吸收的特定子模型。模型的开发、校准和验证利用了在研究单元1320内收集的数据和在协作组的其他四个项目中收集的数据。此外，在开发田间尺度模型解决方案时，将考虑在研究中心运行的更高分辨率的3D根生长模型中关于生物孔特性、根构型和养分吸收的影响的结果和算法。

Quantitative understanding of the interactions between soil structure, soil nutrient pools, root architecture and water and nutrient uptake from subsoils by crops requires approaches that consider the complexity of processes involved including shoot growth, root development, soil water dynamics and soil nutrient turnover. Mathematical modelling provides a helpful mean for the quantitative description of water and nutrient dynamics within the plant-soil system. The central hypothesis of the proposal is that the simulation of nutrient acquisition by crops from the subsoil has to take into account not only crop types with their specific root system, but also soil structure and in particular biopores. We hypothesize that the consideration of the effects of biopore density and quality as well as soil water status on nutrient turnover and accessibility in the subsoil will improve the dynamic simulation modelling of nutrient acquisition by crops at the field scale providing a better basis for improving agronomic management and crops in the future. Specific emphasis is on the acquisition of N and P in interaction with soil moisture conditions and nutrient demand. Using a two-compartment approach, the project develops specific submodels within the modelling framework SIMPLACE for the turnover and uptake of N and P within the soil matrix as well as in the soil biopores. Model development, calibration and validation takes advantage of data which have been collected within the research unit 1320 and data which are gathered in the four other projects of the concerted bundle.In addition, findings and algorithms regarding the influence of biopore properties, root architecture and nutrient uptake from a higher resolution 3D root growth model running at the research center Jülich will be considered in the development of the field scale model solution.