Potassium (K) availability to plants is estimated based on the exchangeable K fraction. Multielement methods increase the analysis efficiency in soil laboratories. The cation exchange capacity (CEC) of soils may affect the prediction of available K. Thus, the purpose of this study was to estimate the available K for corn and soybean in soils in the Rio Grande do Sul (RS) state using Mehlich-1 (M1), Mehlich-3 (M3), ion-exchange resin (resin), ammonium acetate pH 7.0 (AcNH4), and verify whether the CTC affects […]

The adoption of ICP technique to determine P in soil testing has been questioned, due the values determined with this technique is not comparable that those determined with colorimetric method. In the USA, some laboratories are restricted to adopt the ICP technique due the follow reasons: the nutrient recommendations to plants were developed for colorimetric method for P determination; significantly differences have been obtained between P determined with colorimetric and ICP techniques, because the high plasma temperature can measure other […]