Linking soil fertility to food nutrition through soil-crop model simulations
The topic is also suitable for GEM students in track 3 – GEM for Ecosystems & Natural Resources.
Suggested elective courses
- Quantitative Remote Sensing of Vegetation Parameters
- RS & Modelling of Primary Prod of Plant Growth
Statistics, agronomy and programming background/experience recommended.
Crop nutrient concentrations result from the interactions between soil fertility, plant nutrient uptake, and crop growth. We now have detailed nutrient measurements for maize, rice, and wheat from 2023–2024, yet the link between soil nutrient supply and nutrient outcomes in grain remains poorly quantified at field scale. QUEFTS provides a simple but powerful conceptual framework for connecting soil nutrient supply, nutrient uptake, and yield, originally developed for tropical soils and NPK interactions (Janssen et al., 1990). Its principles have since been expanded to diverse environments and crops (Sattari et al., 2014).
The novelty of this work is not the model itself, but the application of a QUEFTS-inspired nutrient simulation framework to macro- and micro-nutrient-rich datasets in a European commercial farm context. By combining soil data, crop measurements, and simple nutrient-uptake functions, the student will produce field-scale estimates of nutrient concentrations that could be extended to satellite-driven monitoring systems. Such nutrient information—resolved in space and time—could support food security assessments, update food composition tables, and inform biofortification efforts aimed at reducing global malnutrition.
The main aim of this topic is to evaluate the ability of a simplified QUEFTS-style nutrient model to estimate macro- and micro-nutrient concentrations (N, Ca, Fe, K, Mg, P, S, Se, Zn) in three global staple crops (maize, rice, wheat). Nutrient and biophysical measurements were collected in 2023–2024 on a large commercial farm near Jolanda di Savoia, Italy, coinciding with multiple satellite (EnMAP, PRISMA, Sentinel-2) acquisitions. This topic uses one or several of these datasets to parameterize and test a lightweight QUEFTS-based pipeline for crop nutrient estimation.
The research can be broken into five main tasks: (i) develop statistical pedo-transfer functions (PTFs) to predict soil nutrient supply from soil properties (SOC, clay, pH, etc.); (ii) compute crop nutrient uptake from measured grain yield × grain nutrient concentration; (iii) fit uptake–supply curves; (iv) fit yield–uptake relationships; and (v) model validation.
The research is linked to an ongoing ESA-funded effort: https://www.eo4nutri.nl/.
Janssen, B.H., Guiking, F.C.T., van der Eijk, D., Smaling, E.M.A., Wolf, J., van Reuler, H., 1990. A system for quantitative evaluation of the fertility of tropical soils (QUEFTS). Geoderma 46(4), 299–318. https://doi.org/10.1016/0016-7061(90)90021-Z