Assessment of Soil Electrical Properties in Selected Agricultural Soils of Puchuncaví, Central Chile

Precision agriculture requires a wide sampling procedure to determine the spatial variability of soil properties for adequate assessment of soil state and appropriate recommendations. Electrical geophysical methods (i.e. vertical electrical resistivity sounding) allow performing rapid measurement of soil electrical properties directly from the soil surface to any depth without any mechanical disturbance of soil cover. Soil electrical properties are linked with many soil properties and could improve the quality and spatial coverage of soil surveys. The results obtained in our study using vertical electrical resistivity sounding confirmed the hypothesis of a high correlation between electrical resistivity and such soil properties as carbon and nitrogen content and silt content. The highest correlation (r > 0.9) was found for electrical resistivity and carbon content. It was also confirmed that significant correlations between electrical resistivity and soil properties are found mainly when soil properties are highly ranged. Perspectives for the applied method lie at the relationship between electrical resistivity and soil properties, such as texture class, clay content, carbon content, and cation exchange capacity. The results obtained in this work could be useful for complex precision agriculture, creating maps of agricultural soils, adequate methods of plant growth, and other issues of precision and conventional agriculture.