Robust automated processing of continuous electrical resistivity measurements for soil texture mapping in support of optimized precision farming

Optimized nutrient and water supply is crucial for enhancing crop yields and ensuring environmental sustainability. As a result, sensor-based, high-resolution soil data, which account for in-field soil variability, are becoming increasingly important for effective nutrient and water management. This paper presents research using electrical resistivity methods, which identify variations in electrical soil properties.

Utilizing rolling electrodes, the GEOPHILUS sensor platform continuously conducts measurements of resistivity data. Soil resistivity is measured by injecting an electrical current into the ground and recording the resulting potential differences between electrodes, introducing an approach to map the bulk electrical resistivity of soils. The system’s design and technical capabilities enable the collection of these parameters at five different depths, reaching approximately two meters, however, the speed of the moving measuring system produces data with substantial distortions, which is why a data pre-cleaning step is required. The main objective involves resistivity data processing and 1D inversions. We have developed a robust code to evaluate and process the data and make 1D inversion for all soundings. Data preprocessing is performed to enhance the reliability of resistivity measurements, improving their suitability for further analysis. This step includes filtering out noise and identifying any outliers. Multiple data processing algorithms were used to enhance the quality of the original data and make them ready for inversion.

Correlation analyses between resistivity and soil texture confirmed strong relationships, with higher resistivity linked to coarser soils and lower resistivity associated with finer soils. The findings validate the approach and its effectiveness in capturing subsurface soil properties.

The developed methodology offers a reliable framework for processing electrical resistivity data, facilitating a more accurate understanding of soil characteristics, which can inform precision farming practices.