Effect of chelating agent treatment on nutrient leaching and crop growth in plastic film house

Soil salinity has an adverse impact on crop productivity and soil ecosystem in plastic film houses.In this study, three chelating agents-ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), and humic acid (HA)-were compared to evaluate reduction of soil salinity and their effect on enhancing crop productivity.A column experiment was conducted to investigate the chelating efficiency of these agents in the soil, and a pot experiment was carried out to examine the growth response of lettuce.Results from the column experiment showed that all three chelating agents released 7 -16% more cations (Ca, Na, Mg, Fe) compared to the control (water treatment only), in the order of DTPA, EDTA, and HA.In the case of NO 3 -, the highest release was observed in the HA treatment, which was 17% higher than the control.For pot experiment, the optimum application ratio for EDTA and DTPA was 0.5 mM and 1 mM for humic acid.When the concentration of EDTA and DTPA exceeded 0.5 mM, or when HA exceeded 1 mM, the growth of lettuce was inhibited, indicating that these higher concentrations had a negative impact of lettuce growth.Overall, applying chelating agents to the soil at optimal concentration can release ions from the soil, which can have a positive effect on crop growth, such as fresh weight.