A Fast Experimental Electrical Conductivity Survey for Agricultural Applications, Case of Small Crop Area of Otoes (Xanthosoma sp.) in Central Region of Panama
Alexis Mojica *
Laboratorio de Investigación en Ingenieríay Ciencias Aplicadas, Centro Experimental de Ingeniería, Universidad Tecnológica de Panamá, 0819-07289 El Dorado, Panamá.
J. Solís
Laboratorio de Investigación en Ingenieríay Ciencias Aplicadas, Centro Experimental de Ingeniería, Universidad Tecnológica de Panamá, 0819-07289 El Dorado, Panamá. And Facultad de Ingeniería Civil, Universidad Tecnológica de Panamá, 0819-07289 Zona 6, Panamá.
N. Bernal
Facultad de Ingeniería Civil, Universidad Tecnológica de Panamá, 0819-07289 Zona 6, Panamá.
F. Vergara
Laboratorio de Análisis Industrialy Ciencias Ambientales, Centro Experimental de Ingeniería, Universidad Tecnológica de Panamá. 0819-07289 El Dorado, Panamá.
B. Duarte
Laboratorio de Análisis Industrialy Ciencias Ambientales, Centro Experimental de Ingeniería, Universidad Tecnológica de Panamá. 0819-07289 El Dorado, Panamá
C. A. Ho
Laboratorio de Investigación en Ingenieríay Ciencias Aplicadas, Centro Experimental de Ingeniería, Universidad Tecnológica de Panamá, 0819-07289 El Dorado, Panamá.
J. Ortega
Instituto Nacional de Agricultura, Ministerio de Desarrollo Agropecuario, Divisa, Panamá.
L. Pastor
Sorbonne Universités, UPMC Université Paris 06, UMR 7619 METIS, F-75005, Paris, France.
*Author to whom correspondence should be addressed.
Abstract
A quasi-continuous automatic recording system of apparent electrical conductivity data of soil (ECâ‚) 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 ECâ‚ 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 ECâ‚ 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 ECâ‚ 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 ECâ‚ and TDS, and pH data.
Keywords: Apparent electrical conductivity (ECâ‚), square quadrupole array, pH, total dissolved solids (TDS), Xanthosoma sp