Fertilizer concentration and fertigation frequency: effects on electric conductivity and ions concentration in the soil solution

Fertirrigation allows total control of the amount of applied fertilizers to the soil as a function of crop demand. Fertigation relies on monitoring of soil ions to obtain the sustainability of soil chemical conditions. The continuous evaluation of ions in the soil solution also contributes to the estimation of the cycling rate of chemical elements and nutrient leaching in the field. The objective of this work was (i) to evaluate nitrate, potassium, sodium and electrical conductivity in the soil solution submitted to different concentrations of injection solution and fertigation frequency during one cycle of the "Grande Naine" banana in a non-cohesive Yellow Latosol and (ii) to evaluate the effects of concentration and fertigation frequency on yields of banana crop. The experiment was carried out according to a randomized block design with six treatments and four replications in a 3 x 2 factorial scheme with three concentrations of the injection solution (3, 10 and 15 g L-1) x two fertigation frequencies (3 and 7 days). The treatments influenced the values of the ion concentration in the soil solution in the soil profile corresponding to the depths of 0-0.30 e 0.30-0.60 m. The concentration of the injection solution and the interaction frequency x concentration influenced the electrical conductivity and nitrate concentration of the soil solution. There was no significant effect of the injection solution and fertigation frequency on production variables.