Elevated Root-Zone Dissolved Inorganic Carbon Alters Plant Nutrition of Lettuce and Pepper Grown Hydroponically and Aeroponically

Summary

Enhancing root-zone (RZ) dissolved inorganic carbon (DIC) levels of plants grown hydroponically and aeroponically can increase biomass accumulation but may also alter plant nutrient uptake. These experiments investigated how bicarbonate (HCO3−) added to a hydroponic nutrient solution and CO2 gas added to an aeroponic system affected biomass and nutrient concentrations of lettuce and pepper plants. Applying high RZ HCO3− concentrations (20 mM) to lettuce plants grown hydroponically decreased foliar N, P, Cu, K, Mn and Zn concentrations, concurrent with decreased biomass accumulation (50% less than control plants). On the contrary, 1 mM RZ HCO3− promoted biomass accumulation (10% more than control plants), but this could not be attributed to higher tissue nutrient concentrations. While eleva