Partial substitution of soluble phosphate by rock phosphate in the planting of Eucalyptus benthamii and Eucalyptus dunnii in southern Brazil
01/Apr/2014
Phosphorus fertilization is important for the initial growth of eucalyptus. Soluble phosphate (SP) sources are commonly used for this purpose because they offer fast dissolution in the soil, but these sources have higher costs than rock phosphate (RP), which has lower solubility. The aim of this study was to evaluate the use of RP as a partial substitute for SP for the initial supply of P to Eucalyptus benthamii and E. dunnii. Two field experiments were carried out (one with […]
Phosphorus extracted by ion exchange resins and mehlich-1 from oxisols (latosols) treated with different phosphorus rates and sources for varied soil-source contact periods
01/Jun/2013
Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of […]
Agronomic performance of phosphate fertilizers in an oxisol under no-tillage
01/Dec/2010
Little is known about the agronomic effectiveness of phosphate rocks in high-yielding crop rotation systems under no-till in the Center-South of the state of Paraná, Brazil. This field study was undertaken to compare the effectiveness of rock phosphates and soluble P fertilizers to increase the yield of several annual crops grown in two consecutive triennial crop-rotation cycles under no-tillage. The experiment was carried out in an Oxisol, in Guarapuava, PR, from 2000 until 2006. Two phosphate rocks (PR – Gafsa […]