A Fast Experimental Electrical Conductivity Survey for Agricultural Applications, Case of Small Crop Area of Otoes (Xanthosoma sp.) in Central Region of Panama

Abstract

A quasi-continuous automatic recording system of apparent electrical conductivity data of soil (ECₐ) was assembled to obtain at a reliable and fast rate, spatial distribution maps of this physical parameter. The device was moved manually throughout several profiles in a small zone of 3753 m2 used for the farming of otoes (Xanthosoma sp.) in Panama, Central America, obtaining 401 voltage values in approximately 20 minutes. These voltages were turned into ECₐ values and mapped. This result was compared with total dissolved solids (TDS) and pH maps of 29 soil samples at 20 cm of depth; salinity was also measured. The ECₐ map presented a zone of high electrical conductivity (130 - 500 μS/cm) on the Eastern part which is consistent with the zones in the TDS and pH maps whose value ranges fall within the optimal threshold for Xanthosoma sp. (45-95 mg/l and 5.5-5.8 respectively). Salinity levels were weak (<0.10%) and are consistent with the zone of high ECₐ typical of non-saline soils. All these results show a significant potential in the use of this mobile system to achieve a fast assessment of agricultural exploitation zones. Finally, a highly moderate correlation is showed among the values of ECₐ and TDS, and pH data.