Quirijn is an active member in the Sociedade Brasileira de Ciência do Solo, and at present serving as coordinator of the soil physics division of that society. Quirijn’s contributions to soil science are focused on the understanding, measuring, and modeling of physical processes in the soil and the soil-plant-atmosphere system. As such, part of the research efforts focuses on the modeling of root water uptake and how we can understand crop water limitations as a function of soil hydraulic properties. This line of research has led to a mechanistic transpiration reduction function incorporating retention and hydraulic conductivity functions, currently incorporated in the SWAP hydrological model. Quirijn also improved algorithms on aeration and osmotic stress.
To apply these models, Quirijn works on the measurement of soil physical properties, especially hydraulic properties in the dry range of tropical soils. To do so, he pioneered an inverse modeling method of evaporation monitored by determining the attenuation of a collimated gamma radiation beam and made novel determinations of these properties in soils from several Brazilian biomes. Furthermore, part of Quirijn’s research activity is dedicated to uncovering uncorroborated indicators of soil physical quality that may hamper real advances in Brazilian soil physics.
Results of his research are published in leading journals, and he publishes regularly in renowned journals worldwide. Throughout his career, Quirijn has advised 12 MS Students, 20 PhD students, 9 Postdocs, and 2 Visiting Scientists.
Quirijn took the initiative to organize, in 2011, a specific event dedicated to Brazilian soil physics, the Brazilian Soil Physics Meeting, a meeting place for Brazilian and foreign leaders and students in soil science. Since the first edition in 2011, the meetings occur every two years and created many opportunities for Brazilian students both during and after their graduation and increased the professional awareness of soil physicists.