Intelligent System for Monitoring Water Content and Solute Concentrations in Soil Cultivated with Fertigated Lisianthus

Abstract

In precision agriculture in fertigated crops it is necessary to optimize the use of water and chemicals, and enable efficient application of fertilizers in order to ensure the best yield and avoid risks of soil salinization and contamination. In this study, an intelligent system was developed with the objective of monitoring, in real-time, moisture and solute concentrations in soil cultivated with lisianthus (Eustoma grandiflorum, var. Casablanca) fertigated under a protected environment. During one crop cycle, moisture was monitored in soil solution using TDR100 reflectometer and solute concentrations were monitored with ceramic cup extractors. Plants were fertigated with a solution containing five potassium concentrations (50, 100, 150, 200, and 250 mg dm-3) applied when the soil reached moisture limits of 0.20, 0.15, 0.13, 0.11, and 0.09 cm3 cm-3. Experimental plots were arranged in a randomized block design in a 5 x 5 factorial scheme (moisture limits x potassium concentrations in soil solution), with four replicates. The proposed intelligent system enabled precise monitoring of moisture and electrical conductivity by TDR, and potassium, and other solute concentrations with extractors, being indicated for the management of lisianthus fertigation under greenhouse conditions with greater environmental safety and reduction of water consumption and risk of salinization.