Effects of humic and fulvic acids on growth of tobacco

摘要: Organic matter was extracted with a mixture of 0.1M Na4P2O7 and NaOH from soil commercial organic product, ‘Aqua Humus’, separated into humic fulvic acids according to their solubility in acid alkaline solutions. They were purified by passage through cation exchange resin, freeze-dried, used for characterization seedling growth studies. The CEC increased pH both acids. Data tobacco studies show that sources root number length at low concentrations while high concentrations, inhibited roots but had no effect. results support the proposition fractions referred as affect development means other than source nutrients.