Nutrients play a pivotal role in resource use efficiency of agricultural systems. At the field level, nutrient recovery from soils and applied fertilisers (organic, mineral or a combination of both) affects environmental impacts such as nitrate leaching or greenhouse gas emissions, but also farmers’ income and yields. These dynamics go across scales, with efficient nutrient use at field scale affecting sustainability of farming systems at regional scale. At the Plant Production Systems group, students can conduct a BSc or MSc thesis looking at a diverse set of agronomic practices to improve sustainability of farming systems, across different soils and climate zones. Such research includes analysis of field experimental data, conducting a farm survey or using integrated modelling approaches. Within this theme, students can also work on an array of related subjects, such as quantitative understanding of principles around dose-response relationships in relation to management practises and environmental conditions, exploration of future nutrient input requirements or societal cost/benefit analyses of nutrient management.
In the Netherlands, the ‘nitrogen-crisis’ has triggered attention for better nutrient management, and tools are being developed to assist farmers in more sustainable nutrient management. This includes use of alternative nutrient sources (such as digestates, nutrients retrieved from industrial or city waste in composted or processed form). Modern agronomy is benefitting from an improved understanding of plant demand and soil supply during the season. With precision technology, major advances can be made in relation to the 4R principles. This has implications on how to manage variability. Research questions focus on spatial and temporal variability and the influence of weather variability on plant demand and soil supply, crop growth and yields, nutrient uptake and nutrient losses, and synergies and trade-offs of adaptations in crop and nutrient management.
In Africa, research questions focus on how to scale better management practices to large numbers of farmers across regions. Insights into agronomic practices often need translation to local conditions and farmer socio-economic circumstances and preferences with the use of decision support tools. At PPS, we work on a number of advisory tools, both in Europe and Africa, for farmers but also for advisors and policy makers. This includes modern digital tools on mobile phones, but also training of extension officers.