Using Water Retention Data and Particle Size Distribution to Characterize Soil Structure Using the European Hydropedological Data Inventory.

Soil water retention characteristics (SWRC) are used to infer pore size distributions that reflect the combined effects of texture and soil structure. A way to isolate and quantify the effect of soil structure from soil texture is to measure the departure of SWRC-derived pore size distributions from a reference distribution that can be attributed to the random packing of soil particles. This can be done with the Kullback Leibler Divergence (KLD) defined as a measure of the distance between two probability distributions. Our objective was to investigate relationships between KLD values and corresponding soil structure description done in the field. KLD was estimated by assuming that pore- and particle-size distributions were log-normally distributed. Data from the European Hydropedological Data Inventory (EU-HYDI) was used to test relationships between KLD, soil structure type and climatic regions.