Navegando por Autor "Inoue, Marcos Yassuhiro"

Agora exibindo 1 - 1 de 1
  • Imagem de Miniatura
    Dissertação
    Acesso aberto (Open Access)
    Capacidade de tamponamento de fósforo em solos do Estado do Paraná
    (Universidade Estadual do Norte do Paraná, 2026) Inoue, Marcos Yassuhiro; Kölln, Oriel Tiago; https://orcid.org/0000-0002-8507-9808; http://lattes.cnpq.br/8041626078120100; Kölln, Oriel Tiago; https://orcid.org/0000-0002-8507-9808; http://lattes.cnpq.br/8041626078120100; Tiecher, Tales; https://orcid.org/0000-0001-5612-2849; http://lattes.cnpq.br/7665378790484936; Silva, Francisco Carlos Mainardes da; https://orcid.org/0009-0004-8008-620X; http://lattes.cnpq.br/9683269855531828; Müller, Marcelo Marques Lopes; https://orcid.org/0000-0002-5466-2398; http://lattes.cnpq.br/3504404305495448; Rodrigues, Diego Resende; https://orcid.org/0000-0002-9495-8943; http://lattes.cnpq.br/9381400899886153
    Phosphorus (P) partial saturation of sorption sites through corrective phosphate fertilization represents a key strategy for improving nutrient use efficiency in tropical and subtropical soils. The State of Paraná does not yet have a formalized and explicit method for recommending corrective fertilization. In this context, the objective of this study was to quantify the phosphorus buffering capacity (PBC) of soils from Paraná, adopting it as a baseline parameter for the recommendation of corrective P rates, as well as to develop predictive models based on clay content and/or remaining phosphorus (Prem). The experiment was conducted at the Soil Laboratory of the State University of Northern Paraná (UENP/CLM). Twenty-six soil samples were collected across the State of Paraná at a depth of 0–20 cm. When necessary, pH correction was performed through incubation with hydrated lime, targeting a pH of 5.5 in CaCl₂. The samples were characterized and incubated for 20 days with 12 different P rates, determined based on the maximum phosphorus adsorption capacity (MPAC), in three replicates. Triple superphosphate was used as the phosphorus source. At the end of the incubation period, soil P contents were determined by Mehlich-1 extraction and quantified using the colorimetric method. Mathematical models were fitted using segmented regression. Phosphorus buffering capacity (PBC) was then determined as the inverse of the slope coefficients of the fitted linear segments. The amounts required to increase soil P concentration by 1 mg dm⁻³ ranged from 2.557 to 58.824 kg P ha⁻¹. Exploratory data analysis enabled the grouping of estimated PBC values into classes according to clay content, organized into a practical interpretation and recommendation table. Mean values ranged from 3.94 kg P ha⁻¹ in soils with less than 250 g kg⁻¹ of clay to 25.89 kg P ha⁻¹ in soils with more than 400 g kg⁻¹ of clay. Considering soils with initial P availability classified as "very low," the required doses to reach sufficiency levels ranged approximately from 135 to 450 kg P₂O₅ ha⁻¹, depending on clay content, indicating that current recommendations may underestimate P requirements in highly clayey soils. Additionally, predictive models were developed using clay content and Prem as single predictors, as well as a multiple regression model incorporating both variables. The inclusion of Prem improved the explanatory power of the model. PBC increased significantly with increasing clay content. The PBC estimation table proved consistent for practical recommendation purposes, although the predictive models showed greater sensitivity in soils with clay contents between 400 and 550 g kg⁻¹. For the State of Paraná, where no formally established method for corrective phosphate fertilization currently exists, phosphorus buffering capacity (PBC) shows potential as a technical tool to support the definition of corrective P application rates.