Electrical resistivity tomography to delineate greenhouse soil variability

Appropriate management of soil spatial variability is an important tool for optimizing farming inputs, with the result of yield increase and reduction of the environmentalimpact of field crops. Under greenhouses, several factors such as non-uniform irrigation and localized soil compaction can severely affect yield and quality. Also, iIf soil spatial variability is not taken into account,and yield deficienciesy are often compensated by extra-volumes of crop inputs; as a result,, over-irrigation and over-fertilization in some parts of the field may occur. Technology for spatially-sound management of greenhouse crops is therefore needed to increase yield and quality and to address sustainability. In this experiment 2D-Electrical resistivity tomography (ERT) was used as an exploratory tool to characterize greenhouse soil variability and its relations to wild rocket yield. Soil resistivity well matched biomass variation (R2=0.70), and was linked to differences in soil bulk density (R2=0.90) and clay content (R2=0.77). ERT shows a great potential in horticulture where there is a growing demand of sustainability coupled with the necessity of stabilizing yield and product quality