@article{oliveira_novais_smyth_neves_2000, title={Aluminum diffusion in oxisols as influenced by soil water matric potential, pH, lime, gypsum, potassium chloride, and calcium phosphate}, volume={31}, ISSN={["0010-3624"]}, DOI={10.1080/00103620009370606}, abstractNote={Abstract Plant root exposure to soil aluminum (Al) depends on the soil solution Al concentration and transport to the root by diffusion. Changes in Al diffusive flux for two Oxisols was measured under laboratory conditions as a function of pH, water matric potential, and applications of gypsum, potassium chloride, and calcium phosphate. Double‐faced cation exchange resin sheets served as sinks for Al transported during 10‐day incubations through chambers containing 314 cm3 of soil. Across a range of soil pH values from 4.5 to 5.5, maximum diffusive flux of Al occurred at pH values of 4.7–4.8 in both soils and corresponded to increases of 2.2–3.0% relative to the unlimed treatment. Between pH values of 4.7–4.8 and 5.4, diffusive flux of Al decreased by 38 and 46% in the two Oxisols. Diffusive flux of Al decreased by 16–20% for the two Oxisols as soil water potentials decreased from ‐10 to ‐200 kPa. Magnitude of the reductions in diffusive flux of Al with decreasing soil water potential were less than those reported for diffusive flux of phosphorus (P) in prior investigations. Diffusive flux of Al increased by as much as 4‐fold with additions of CaSO4 and KCl, which increased the soil solution Al concentration. Additions of 400 mg P dm‐3 of soil had no effect on Al diffusion in either Oxisol.}, number={15-16}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Oliveira, FHT and Novais, RF and Smyth, TJ and Neves, CJL}, year={2000}, pages={2523–2533} }
 @article{oliveira_novais_smyth_neves_2000, title={Comparisons of phosphorus availability between anion exchange resin and Mehlich-1 extractions among oxisols with different capacity factors}, volume={31}, ISSN={["0010-3624"]}, DOI={10.1080/00103620009370464}, abstractNote={Abstract Acid and dilute‐salt chemical extractants are commonly used to assess and adjust phosphorus (P) availability in soils. Soybean was grown for 45 days under greenhouse conditions on samples of 10 Oxisols treated with variable levels of soluble P to compare critical soil P levels between an anion exchange resin (AER) and the Mehlich‐1 extractant, and to evaluate the influence of the soil P capacity factor (PCF) on the critical soil P levels. Variation among soils in the quantities of extracted P and critical P levels with the AER was less than that with Mehlich‐1. Low correlation values between soil characteristics related to PCF and measurements of AER soil P suggested that the AER method was not as sensitive to variations in soil PCF as Mehlich‐1. Interpretations of AER critical P levels, therefore, do not need auxiliary measures of PCF as with the Mehlich‐1 extractant. The reverse was true, however, for P uptake. Therefore, the criteria used to assess plant response to P (P uptake or dry matter production) in soils with variable PCF will influence the results obtained in correlations between methods used to extract soil P.}, number={5-6}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Oliveira, FHT and Novais, RF and Smyth, TJ and Neves, JCL}, year={2000}, pages={615–630} }