Dosagem de sulfato por turbidimetria em solos tiomórficos

• Published in: Acta agronomica (Palmira) 2014-05, Vol.63 (1), p.42-47
• Main Authors: Combatt Caballero, Enrique Miguel, Alvarez V, Victor Hugo, Ferreira Santos, André
• Format: Article
• Language: English
• Subjects: Soil sciences; Surfactants
• ISSN: 0120-2812; 2323-0118
• DOI: 10.15446/acag.v63n1.31922

The objective has been compare three surfactants in dosage of sulfur available in acid sulphate soils. Were collected 12 Soil samples in the State of Esprito Santo - Brazil and in Crdoba Colombia. To evaluate the effect of surfactants in the preparation of 20 ml suspension of reading, has been selected 5 ml of suspension and was added 15 ml of working reagent. The 15 ml had 0.8 g of BaCl2 and the treatments were: 8 mg gum arabic, or 0.15 ml Tween, or 30 mg polyvinyl alcohol.In addition to this, was applied 0.15 ml of HNO3/lt at a concentration 50mmol, in order that pH of the reading suspensions had been between 3 and 3.3. The sulfur was extracted with Ca (H2PO4)2, 500 mg/lt P in HOAc 2 mol/lt and determined by turbidimetry. For comparison of the surfactants were used three replicates by dosage and the data were analyzed by t test, to comparison between two methods was applied statistical test of identity of two methods. It can be concluded that the surfactant gum arabic showed the best performance in operational terms, but it is also possible to use polyvinyl alcohol for the quantication of S-SO42-.