Methods of modeling and mapping of the soil bulk density: a case study from Chernivtsi region, Ukraine

Soil monitoring programs in many countries often do not measure such an indicator as soil bulk density. At the same time, modern problems of assessing the condition of the soil cover require its use in soil management of agricultural landscapes. We see the solution to this problem in geospatial modeling. We have developed a technique for simulating soil bulk density, the algorithm of which consists of five stages: the creation of model maps of agro-industrial soil groups, modeling of a clay content map, construction of a map of humus content, selection of empirical dependences of soil bulk density on humus and clay content with evaluation reliability of these dependencies and their implementation in GRASS GIS and, finally, cartographic modeling of the spatial continuous distribution of soil bulk density. At the same time, parameters for improving the quality of methods modeling and mapping the soil bulk density were established. First of all, this is an increase in the sampling dataset of density, humus, and clay content to improve the reliability of the selected regression formula. It is also an improvement in the quality of spatial modeling of the humus content using geostatistical methods or modeling. To improve the clay content map, it is necessary to increase the resolution of DEM and predictors, to choose more accurate sources of DEM and prediction algorithms. The application of the presented methodology is shown in a part of Chernivtsi region, Ukraine, with the possibility of use on the scale of the entire country. URL: https://www.gcass.science.upjs.sk/