Effect of Salt Stress and Humic Acid on Tomato Plants (Solanum Lycopersicum)

Abstract

This study aims to investigate the effect of salt stress and humic acid on the growth of tomato plants (Solanum lycopersicum) under a controlled irrigation system regulated by a specific scale. Salinity is one of the most significant environmental factors that negatively affect plant growth and productivity by disrupting water and nutrient uptake. Conversely, humic acid is used as a bioactive organic compound to improve soil fertility and enhance plant tolerance to adverse environmental conditions. Tomato plants were exposed to different salinity levels with the application of humic acid at specific concentrations. Changes in vegetative traits (such as plant height, number of leaves, and fresh and dry biomass of shoots) as well as nutrient concentrations in plant tissues were monitored. The results showed that salt stress caused a significant decrease in vegetative growth parameters and a reduction in the uptake of some essential nutrients. In contrast, the use of humic acid clearly mitigated the adverse effects of salinity by promoting growth and improving nutrient absorption, indicating its effectiveness as an inducer of salt stress tolerance in tomato plants.