Degradation of autotoxic chemicals and maintainence of electrical conductivity recover growth, yield and nutrient absorption of successive lettuce in recycled hydroponics.

In recycled hydroponics, successive crop cultivation by maintaining electrical conductivity (EC) suffers lower growth performance due to accumulating autotoxic root exudates. In this study, the efficiency of alternate current electro degradation (AC-ED) was evaluated for degrading allelochemicals and recovering retarded lettuce yield cultivated in EC-adjusted repeatedly used nutrient solutions. From benzoic acid (BA)-added nutrient solution, BA was completely degraded after 24 h by applying AC-ED at 551 and 940 Hz frequency with 50 and 80% electrical duty.