Kees Jan is a biogeochemist passionate about understanding how plants and soils react to environmental changes and different management practices. His work explores carbon and nutrient cycles across diverse ecosystems, including grasslands, croplands, and temperate forests. He is particularly interested in the role of soil microbes in these cycles, which he studies using methods such as incubation experiments, isotopic tracers, and biomarker analyses. Kees Jan uses meta-analytic techniques to bring together findings from many studies, offering a big-picture view on issues related to food security, climate change impacts, and sustainable agricultural practices.  Recently, he has focused on rice cropping systems, aiming to reduce their environmental footprint while boosting rice yields.