The objective of this work was to evaluate porous ceramic cups to observe electric conductivity and potassium concentration in soil solution. An area cultivated with tomatoes under fertirrigation with three potassium levels and application frequencies of one and three days, was used. Values for electric conductivity and K concentration were corrected for moisture using saturated pastes as a function of different soil moistures. Values for electric conductivity obtained with porous ceramic cups underestimated by approximately 16% these characteristics measured in the saturation paste extract. The same tendency was observed in the K concentrations, being underestimated by approximately 10%. Coefficients of variation (R²) were greater by 0.7 for the two analyzed variables. Results showed that electric conductivity and K concentration can be analyzed through the solution extractors with an acceptable precision.
ceramic cups; electric conductivity; potassium; fertirrigation
