Physicochemical Characteristics of Leachates from Soilless Substrates for Tomato (Solanum lycopersicum L.) Seedling Production

Abstract

Assessing agricultural water quality is fundamental to minimizing and mitigating irrigation's environmental impacts. Leachate dynamics and physicochemical parameters as environmental stress indicators were evaluated. For tomato (Solanum lycopersicum L.) seedling production, we used soilless substrates. The study evaluated four treatments: T1 (100% coconut fiber), T2 (75% coconut fiber + 25% perlite), T3 (100% peat moss), and T4 (75% peat moss + 25% perlite). A controlled irrigation regime lasted 16 days, including fertilizer and fungicide applications. We collected and analyzed 192 leachate samples for eight parameters. Measured parameters included pH, electrical conductivity (EC), total dissolved solids (TDS), Na⁺, NO₃⁻, K⁺, and Ca²⁺. T3 showed the highest average volume retained (AVR). T2 exhibited the highest average leachate volume (AVL). Nitrate concentrations were higher in T4 and lower in T1, exceeding regulatory limits. Concentrations of Na⁺, K⁺, and NO₃⁻ posed contamination risks. These findings highlight the need for improved monitoring to enable safe agricultural reuse.