Phosphorus fractions in apple orchards in southern Brazil

• Autor(a) principal: Schmitt, Djalma Eugênio
• Data de Publicação: 2017
• Outros Autores: Brunetto, Gustavo, Heberle, Elaine dos Santos, Wagner, Winicius de Lima, Sete, Paula Beatriz, Souza, Monique, Ambrosini, Vítor Gabriel, Santos, Matheus Ademir dos, Tiecher, Tales, Comin, Jucinei José, Couto, Rafael Rosa, Gatiboni, Luciano Colpo, Giachini, Admir José
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/186112
• topic: Pomar; Maçã; Fósforo; Fertilizante fosfatado; Manejo do solo; Apple orchard; Phosphate fertilization; P chemical fractionation

Phosphorus (P) applications at dosages higher than the necessary may cause P buildup in the soil labile fractions and, consequently, pollution of water sources. This study aimed to assess accumulation of P fractions as well as the parameters of adsorption isotherms in soil profiles having a history of application of phosphate fertilizers and cultivated with apple trees. Soil samples were collected from an area with no history of cultivation and 2 apple orchards cultivated for 8 (P8) and 18 (P18) years, in the city of Urubici, Santa Catarina, southern Brazil. Soil samples were air dried, sieved in a 2-mm mesh, and subjected to chemical analyses (P adsorption) besides P chemical fractionation. Applications of phosphate fertilizers to the orchards, particularly P18, increased the inorganic and organic concentrations of P in all fractions. The distribution of P in organic and inorganic forms in the planted soils was similar to the distribution observed for the native vegetation soil. The highest inorganic labile P fraction, the lowest maximum P adsorption capacity, and the highest equilibrium concentration values at P18 are indicators of a higher environmental pollution risk of the orchards soils compared to the native soil.